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PRACTICAL FLYING 

A MANUAL ON FLYING DEALING 
WITH THE MOST RECENTLY 
ADOPTED METHODS OF TUITION IN 
THE COMPLETE FLYING COURSE. 
WRITTEN AND ILLUSTRATED BY 
EXPERIENCED FLYING OFFICERS. 



A NIGHT LANDING 

Aided by the light of a parachute flare, dropped from the 

machine, and wing lip flares. 



PRACTICAL FLYING 

Complete Course of Flying 
Instruction 



BY 
FLIGHT-COMMANDER 

W. G. McMINNIES, R.N. 



t« 



with an introduction by 
Major-General W. S. BRANCKER, C.M.G. 

COMPTBOLX£R-GENERAL OF EQUIPMENT OF THE BOTAL AIB FOBCE 

ILLUSTRATED BT 

Flight-Lieutenant E. L. FORD, R.N. 

WITH A CHAPTER ON THE BfEDICAL ASPECTS OF AVIATION BT 

H. GRAEM ANDERSON. M.B.. Ch.B., F.R.C.S. 



NEW YORK 
GEORGE H. DORAN COMPANY 



Copyright, 1918, 
By George H. Doran Company 



Printed in the United States of America 



228259 

OCT 15 1919 

INTRODUCTION 

THIS book appears at a propitious amount; the Royal 
Air Force is in the throes of creation, and the strong 
individualities of the Royal Naval Air Service and the 
Royal Flying Corps are in the course of fusion. 

It is the work of a Royal Naval Air Service officer, and 
besides being a valuable addition to existing official publica- 
tions, it reveals to the pilots of the Royal Flying Corps the 
principles and methods of the Service with which they are 
to share a great and glorious future. 

Aviation has shown the world some wonderful steps in 
progress during this War, not the least noteworthy of which 
has been the advance made in our methods of training. Ex- 
perience, courage and patience have built up a system which 
has completely revolutionised old ideas, and pilots to-day 
are performing evolutions with the utmost confidence which 
eighteen months ago meant almost certain death. 

The responsibilities of the flying instructor are great, and 
his work hard and unceasing. His is the dull round of duty 
day after day, without the glamour and excitement of serv- 
ice in the Field, and often without the appreciation which 
it deserves. It is, however, on his courage, patience and 
energy that we depend for the maintenance in the future 
of that individual superiority which our pilots have so 
clearly demonstrated in the past. 

Every day confirms the growing importance of aviation 
in war; indeed, it seems that all other means of bringing 
the enemy to his knees have almost ceased to progress, 
whilst our aerial fleets go on expanding and improving until 
at last they will bring us victory. 



20th March, iQi8. 




%^^ ^ y^^^^UA^^ 



PREFACE 

EVERY prospective pilot who is really interested in his 
work must have been struck with the dearth of liter- 
ature dealing with practical flying. When the writer 
was learning to fly he searched everywhere for practical 
information on aviation, and studied all the available litera- 
ture on the subject, but found most of it lacking in the very 
features he required. Even to-day, most books on flying 
are either far too advanced, dealing principally with the 
theoretical aspect of aviation, or else contain historical and 
personal, instead of practical^ reminiscences. There seem 
to be few books written by experienced pilots in such 
simple language that a man who had never seen an aero- 
plane before might understand and appreciate the informa- 
tion, hints and advice given. It has been the writer's object 
to produce such a book, giving as much useful and prac- 
tical information on elementary flying as space permitted. 
It is not pretended that it possesses any great literary merit, 
but it is hoped that it may be of use to those now learning 
to fly, as a good deal of the matter was originally given in 
lecture form to officers when undergoing their preliminary 
training at a flying school. It does not pretend to appeal to 
the expert pilot or the individual interested in 'the more 
technical or theoretical side of aviation. The idea has been 
rather to present to the prospective pilot, in terms that can 
be easily understood, a general impression of how flying is 
taught and learned. Forewarned is forearmed, and it is 
hoped that, by studying the advice and hints contained in 
the chapters on elementary flying, the beginner will be able 
to avoid many of the mistakes so commonly made while 
under instruction. 

At the moment of going to press, the fusion of the Royal 
Naval Air Service and the Royal Flying Corps is taking 
place, and by the time the book is in the hands of the 

ix 



X PREFACE 

reader it is anticipated that the flying services will be con- 
solidated under the title of the Royal Air Force. 

Owing to the rapid changes which take place in flying, 
training systems and machines may also vary from time to 
time as new and improved methods are introduced, and, 
therefore, due allowance must be made for them in reading 
the book. If any important corrections are necessary be- 
tween the time the bulk of the pages go to press and publi- 
cation, they will be found in the addendum at the end. 

Both R.F.C. and R.N.A.S. officers who were instructing 
at the same flying school as the writer have rendered him 
valuable assistance in producing the book, and his thanks 
are due to them for their suggestions and advice. 

The sections of the Ordnance Survey maps and Charac- 
teristic Sheet, pages 121, 122 and 139, are reproduced 
with the sanction of H.M. Stationery Office. 



CONTENTS 



PAGE 
INTRODUCTION BT MAJ.-GENERAL BRANCKER vii 

PREFACE ix 

CHAPTER I 

PRELIMINARY CONSIDERATIONS 

Men that Make Good Pilots — Safety of Flying — Summary of 
Preliminary Studies i 

CHAPTER II 

THEORY AND PRACTICE OF FLIGHT 

Principles of Flight — Explanatory Description of the Controls — 
The Engine — ^Aeroplane Construction 7 

CHAPTER III 

ELEMENTARY PRINCIPLES OF AEROPLANE ENGINES AND CAUSES OF 

ENGINE TROUBLE 

How a Four-cycle Engine Works — Valve Systems of Different 
Typesr— Stationary and Rotary Engines — Parts that Give 
Trouble — Diagnosing Engine Breakdowns — Common Engine 
Failures — General lunts on Running an Engine 21 

CHAPTER IV 

THE FIRST LESSON IN THE AIR 

Flying Straight, Laterally and Horizontally Level — Bumps, 
Turning — Getting Off and Landing — ^When to Take the First 
Solo Flight 45 

CHAPTER V 

THE FIRST SOLO FLIGHT AND AERODROME PRACTICE 

Preliminary Attention to Engine and Machine — Starting Up — 
Signals to Mechanics — Getting Off — Turning — ^At 1000 ft. Up 
—The Rule of the Air — Landing — Taxying — Obtaining a Pilot s 
Certificate » 63 

xi 



xii CONTENTS 

PAGS 

CHAPTER VI 

THB USE AND WORKING OF THE INSTRUMENTS 

The Principal Instniments Used — Their Working — How One 
May be Substituted for Another 88 



CHAPTER VII 

MAP READING 

Principal Terms Used — Reckoning the Scale — Contours — ^Fea- 
tures — Map Symbols — Ideal Map for Aviation 113 

CHAPTER VIII 

PREPARING FOR A CROSS-COUNTRY FLIGHT 

Marking up a Map — Working out Deviation — Swinging a Com- 
pass — The Wind Factor — Calculating Radius of Action — 
Finding One's Bearings — The Inter-relationship of Landmarks 
— How to Carry the Map — Position and Comfort — Clothing — 
Goggles 125 

CHAPTER IX 

CROSS-COUNTRY FLYING 

The Height to Fly — Storms, Fog and Clouds — Taking Bearings 
in Day-time and at Night — Landing on Strange Ground — Re- 
starting from a Field — A Forced Lamding — Making Use of the 
Wind when Landing — Selecting Suitable Landing Ground — 
Making an "S" Turn — Turning Near the Ground — Steps to 
Take After a Forced Landing — Starting up Without Aid — 
Swinging a Propeller — Starting a Rotaiy Engine — Causes of 
Engine Failures — Examples of Good and Bad Airmanship . 146 

CHAPTER X 

MORE ADVANCED FLYING 

An Ascent of 10,000 ft. — ^A Vertical Bank — Spiral Descents — 
"Zooming" — Nose Diving — Looping — Tail Sliding and Spin- 
ning — Horizontal Rolling; — Rolling and Staggering — ^The Im- 
meSnann Turn — Exhibition Trick Flying 186 



CHAPTER XI 

NIGHT FLyiNG 

Aerodrome Lighting — Daylight Practice — Getting Off at Night — 
Night Landing — Night-flying Equipment — Setting Out an 
Aerodrome * 200 



I 



CONTENTS xiii 

CHAPTER XII 

THE GROWTH OF CONFIDENCE — A WORD BOTH TO INSTRUCTORS AND 

PUPILS 

PAGE 

Instilling Confidence — ^After a Crash — Advantages of Consider- 
able Practice — Advanced Dual Control — ^When a Pupil Can 
Fly — ^The Time Taken in Learning 207 

CHAPTER XIII 

THE MEDICAL ASPECTS OF AVIATION WITH SOME NOTES ON SUITABLE 

CLOTHING 

By H. Graem Anderson, M.B., Ch.B., F.R.C.S., Temp. 
Surgeon R.N,, Attached to St. Mark's and the Belgrave 
Hospitals 

Physical Fitness — ^Reflex Actions — Thte Visual Reflex — The Audi- 
tory Reflex — ^Tactile and Muscular Reflexes — The Balancing 
Reflex — Drinking and Smoking — Over Confidence — ^What to 
Wear — Frostbite — ^Air Sickness 214 

APPENDIX 

Flying Instruction Notes in Brief — General and Condensed 
Hints in Definite Stages for the Guidance of Pupils . . 219 

Glossary of Terms Commonly Used in Aviation 229 



PRACTICAL FLYING 



PRACTICAL FLYING 

CHAPTER I 
Preliminary Considerations 

BEFORE deciding to take up aviation, either as a 
hobby or as a profession, it would be as well for 
the aspirant to a pilot's certificate to consider whether 
he is suitable for it, both mentally and physically. Generally 
speaking, anyone of average health and intelligence can be 
taught to fly, but at the present time there are compara- 
tively few who will make really first-class pilots. In peace 
time the demand will be greater for the ordinary class 
of pilot, and a much lower level of skill will be required 
than in war time. 

Which Men Make Good Pilots? 

It is not an easy matter to determine beforehand which 
men are likely to make good pilots and which are not. 
Generally speaking, the average man will make a fair 
pilot. There are a few people who arc bom aviators, and 
there are some, either owing to natural nervousness or 
because flying does not appeal to them, who will never 
become pilots at all. 

Sometimes, before undergoing any instruction whatever, 
a pupil is subjected to fancy flying with a view" to testing 
his nerves; but such a trial is apt to be misleading in its 
results. It is far better to instil confidence in a pupil by 
showing him how safe and secure he is in ordinary flying 
than to attempt to scare him in his first flights by steep 
spirals, nose dives, or loops. The growing confidence of a 
pupil in himself and in his machine should be culti- 
vated. 

Many people imagine that motoring or motor cycling 
forms an excellent apprenticeship to flying ; but beyond the 

1 



2 PRACTICAL FLYING 

fact that these pastimes provide the learner with useful 
mechanical knowledge, they will not be found to be of par- 
ticular value to the aviator. It is the man who has been 
accustomed to riding and outdoor games who proves quick- 
est at picking up the feel of an aeroplane and whose 
eye more rapidly adapts itself to the speeds and angles 
encountered when flying. 

During his first few flights the pupil will have to ac- 
custom himself to the feeling of being in the air. This is 
quite one-third of the battle, and it is for this reason that 
observers and balloonists, who have already overcome the 
strange sensation of being up aloft, learn the actual han- 
dling of the machine more quickly than the complete novice. 



1 V 



/ 



> jjh- '^ When Not Suited to the Work 

\y- ' \ Under present conditions, it is a mere waste of time, both 
for the instructor and for the pupil, if the latter is not 
really keen on his work. If he decides, after five or six 
hours' dual-control instruction in the air, that he is not 
suited to the work, or has not sufficient stamina to carry 
on with it and overcome any preliminary nervousness 
that may assert itself, he had far better have left it alone 
in the first place. 

It must not be thought from these remarks that aviation 
is a difficult or dangerous pursuit. Although great promi- 
nence is given in the daily Press to accidents in the air, 
iSiese occur very seldom when the total number of pupils 
under training and the number of hours flown daily are 
taken into consideration. Accidents are generally due to 
inexperience on the part of pupils in their early training, 
which is probably speeded up, increasing the risk in con- 
sequence, more than it would be if the call for pilots were 
not so urgent. Apart from these causes, air accidents are 
very few and far between. 

An aeroplane is a very simple type of machine com- 
pared with a motorcar, for instance. There are far fewer 
parts to go wrong. There is practically no transmission 
to give trouble, no gearbox, clutch or differential to break 
or require daily attention. The tyre problem on the aero- 
plane hardly exists. A dozen control wires, generally dupli- 



SAFETY OF FLYING 



but noV *V V>olr>V5 ft . 



3*Tu^ or 



or iTawe machine &t ^int'j ^w^^rt«d b^' 



Ground training. Where and where not to man-handle an aero- 
plane. Always lift under struts a.nd spars, and not under unsup' 
ported lei^ths. Never lift or push by holding on to the leading 
or trailing edge of a wi:^. 

cated, are the only vital parts of the machine where 
failure might mean an accident. Compare them with the 
hundreds of parts in a motorcar which may go wrong, and 
some idea of the safety of the flying machine, from the me- 
chanical point of view, can be obtained. Again, motorcar 
accidents are often due to the carelessness of the drivers 
themselves: collisions on blind comers or at crossroads, 
sideslips and skids on tramlines may be quoted as familiar 
examples. In the air there is unlimited space for machines. 
They are not confined to certain narrow tracks, and hence 
accidents are scarce where trained pilots on standard de- 
signs of machines are concerned. 

Where accidents do occur generally is in getting off or 
in landing, but the risks attaching thereto can be practically 
eliminated by care on the part of the pilot. Modem fly- 
ii^ — except that under war conditions — ^has arrived at a 



PRACTICAL FLYING 




The proper way to lift the wings and tail of an aeroplane. 

point where it has already been considered as a rival to 
other methods of travel, and it is probable that, in the 
near future, it will compete successfully with the motor- 
car or mail train over long distances, hence the wonderful 
opportunity for the younger generation to take up this 
new science and to be ready to make use of the opportuni- 
ties it will offer when the war comes to an end. 

Physical Requirements 

To return to the case of the prospective pilot. It is gen- 
erally admitted that he must be as physically fit as possible. 
His sight should be perfect, and although there are cases 
of pilots with half normal vision, necessitating the use 
of spectacles, there is the ever-present danger of the glasses 
breaking or becoming dimmed with oil or rain, and a con- 
sequent danger in landing. 

Sound heart and lungs are the next most important points. 
A war pilot may be required to stay for several hours at 
heights varying from 15,000 ft. to 20,000 ft., and unless 



GROUND TRAINING 



5 



he is in the best possible health he will be unable to do 
this. Of course, under peace conditions the requirements 
would not be so strenuous, the average height for com- 
mercial flying probably being approximately 4000 ft. or 5000 
ft. 

/ ^ i^\^"'*^'^ Preliminary Study of Aviation 

-^ All Service pilots have to pass a fairly stiff medical exam- 
ination, so that there is not much chance of the physically 
unfit becoming aviators. Once through the medical exami- 
nation, the prospective pilot is drafted away to a flying 
school, where, probably, he will have his first close view 
of an aeroplane. He may spend several weeks on the 
ground before making his initial dual-controlled ascent. 
This time can be employed to great advantage by a close 
study of the machine and by learning from the mistakes 
committed by pupils in a more advanced stage of training. 



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How to make loops in piano wire for attaching to the turn-buckles, 
etc. The top points of the round-nosed pliers used for this opera- 
tion only are shown. 



6 PRACTICAL FLYING 

A keen pupil will spend as much time as possible in study- 
ing aviation handbooks and such literature dealing with 
the subject which may come his way from time to time. 
He should also do as much practical work on the machines 
as he can. It is always better for him to do the work 
himself than to watch it being done by others. For in- 
stance, a pupil will learn more in an afternoon by helping 
to dismantle a machine after a crash than he would have 
done by watching for several weeks the mechanics effecting 
minor adjustments to a machine in the shed. 

Preparatory Ground Training 

The following is a summary of the various points which 
should be studied in a preliminary ground training : — 

( 1 ) The pupil should first of all make certain that he 
is physically fit enough to fly, and that he is sufficiently 
keen and interested in aviation to be able to overcome 
any preliminary nervousness or difficulties that may be 
experienced in the early stages, otherwise he will be 
simply wasting his own and his instructor's time. 

(2) During the pre-air work period of instruction 
the pupil should familiarise himself with the mechanical 
details of the machine on which he is going to be 
taught. He should then find out how the controls, 
levers, taps, switches and instruments work, and what 
is the proper speed to fly, glide and climb the machine 
and to run the engine. 

' (3) He should be able to do a certain amount of 

practical work on the machine, i.e., change plugs, start 
up the propeller, splice wire, make loops and eyes, etc. 
He should learn how to man-handle an aeroplane, at 
what points he can lift and move it, and those where it 
is undesirable to exert force. 

(4) He should study as much aviation literature as 
he can obtain, and learn, at any rate, the rudiments of 
mechanical flight, the construction of aeroplanes, and 
the principles on which the petrol engine works. The 
last is most important. 



I 



CHAPTER II 
The Theory and Practice of Flight 

T is necessary for the pupil to understand why an aero- 
plane flies, and thoroughly to master the objects and 
uses of the various controls. 

Why an Aeroplane Flies 



At first glance, it is not easy to see why an aeroplane 
flies. The pupil may have watched a machine run along 
the field for some distance and then gradually leave the 
ground. He has seen no lever move. Indeed, if he had 
been in the machine, it is doubtful if he would have detected 
any movement of the controls, and yet the machine, which 
was running along the ground a second or two before, is 
now in the air and, apparently, climbing quickly. An aero- 
plane flies because the propeller, driven by the engine, forces 
the planes, which are set at a small angle to the air, through 
the air at high speed, and a lifting action is thereby set up. 
Naturally, if the lifting action, depending on the speed at 
which the machine is forced through the air, is not great 
enough to lift the weight of the machine, the aeroplane will 
continue to run along the ground. Once sufficient speed 
has been attained, however, it will rise in the air, if the 
elevator is in the correct position. 

It must always be remembered that it is the relative speed 
between the aeroplane and the air that assists the machine 
in flight. Ground speed is only identical with air speed 
when there is no wind; thus, if a machine were flying 
against a wind of 20 m.p.h., and the necessary difference of 
speed between the machine and air, in order to maintain 
the aeroplane in flight, were 50 m.p.h., the speed of the ma- 
chine over the ground would only be 30 m.p.h. If, however, 

7 



8 PRACTICAL FLYING 

the machine were to turn down wind, its ground speed 
would increase to 70 m.p.h. to reach its flying speed of 50 
m.p.h., which always remains constant within certain limits. 
Many pupils find it very difficult to realise that their speed 
through the air is independent of the speed of the wind, 
although their speed over the ground is very greatly influ- 
enced by the speed of the wind, which may be adverse or 
favouring. For this reason it is possible for a machine to 
remain stationary over the ground if it be fljring against a 
very strong wind, in which case the speed of the wind and 
the Qying speed of the machine would be identical. 



An Explanation of the Controls 

The object now should be to discover how the machine 
is controlled. If the pupil inspects the pilot's seat, or, bet- 
ter still, sits in the machine on which he is shortly going to 
be taught to fly, he will find projecting from the floorboards 
between his knees a vertical control column, generally known 
as the "joy stick." His feet will be touching the rudder 
bar, and by working the stick and bar, and by observing the 
effect they have on the controlling surfaces of the machine, 
he can gain an excellent idea as to how the aeroplane can 
be made to climb or descend, turn, and fly in any desired 
direction. 

The Rudder Bar 

Consider the rudder bar first. This probably is a metal- 
lined piece of wood pivoted about its centre, so that the 
pilot's feet can swing it backwards and forwards round that 
centre* It is set athwartships, and at each end are control 
wires, sometimes duplicated, which connect the rudder bar 
with the ruddering surfaces of the machine. The rudder 
is situated at the stem, and consists of one or more vertical 
surfaces set parallel with the fore-and-aft line of the ma- 
chine. Controlling wires are adjusted to such a length that 
when the rudder bar is dead athwartships the controlling 
surfaces are perfectly parallel with the fore-and-aft line. 
With the rudder bar square, the machine will fly straight; 



THE CONTROLS 





Cmblc5 
Comcch'n^ 

K> Ruddar. f 







.neutral. 



Turning , 
to tHa, 

Air 5VrMcii\() 

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PLAN View 




The effect of ruddering. 

but when the right side is pushed forward it pulls the con- 
trolling surfaces to the right from its point of attachment 
(see sketch), and so opposes more surface to the wind on 
that side, which causes resistance and forces the tail of the 
machine round in the opposite direction, i.e., to the left. If 
the tail goes round to the left, the fore part of the machine 
will turn to the right, so that, to cause the machine to turn 
to the right, all that one does is to press the right foot for- 
ward on the rudder. The reverse is the case when it is de- 
sired to turn the machine to the left. 



The "Joy Stick" 

To make a correct turn, however, it is necessary to do 
more than press the rudder. The vertical control column, 
which has already been mentioned, is now called into oper- 
ation, and must also be moved in the desired direction. This 
control column is pivoted about three-quarters of the way 
down and can be moved backwards, or forwards, or side- 



10 



PRACTICAL FLYING 



ways from this point. It is used to control the elevator and 
ailerons of the machine. 



TTie Elevator 

The elevator, like the rudder, is situated at the back of the 
machine, except in certain old-fashioned types, where a 
front elevator is fitted. The elevator is a horizontal con- 




The elevator. The effect of the fore and aft movement of the 
control lever on the elevator and the machine as a whole. The con- 
trol is pulled back to make the machine climb, and pushed forward to 
make it descend. The centre position the machine flies level when 

the engine is running. 

trolling surface, or flap, set parallel with the main planes, 
and capable of being worked upwards or downwards from 
its hinged or pivoting forward point. It is connected to the 
"joy stick" on control column by wires (generally duplicated 
for safety's sake), the wires being arranged above and be- 
low the pivoting point of the control lever, so that when the 



THE ELEVATOR 11 

lever is pushed forward the elevator surface moves down 
from its forward hinged end, presenting more surface to 
the air, causing a resistance which sends the tail of the 
machine up and the nose of the machine down. It will be 
seen from this that, to make the machine descend, the con- 
trol lever must be pushed forward, and to make it climb it 
must be eased back. In the latter case the elevator surface 
will be raised above its neutral line, so that it presents its top 
surface to the air ; the resistance encountered then sends the 
tail of the machine down and the nose up, and the machine 
is now ascending. 

When the elevator is neutral, the control wires being con- 
nected to the joy stick, the latter must also be set in the 
neutral or vertical position. Where the control wires are 
connected directly between the control column and the ele- 
vator, it will be obvious that, to ensure the correct control, 
the wires must be crossed before being connected to the 
elevator, i.e., the wires from above the pivoting point of the 
control column lead to the underside of the elevator and 
vice versa. (See sketch.) 

All the movements of the control lever are natural ones, 
i.e., to make the machine descend the lever is pushed for- 
ward; to climb, it is pulled backward; and to turn to the 
right or left, it is moved in those directions. 



How "Stalling" is Caused 

The attitude of the machine in the air is controlled by the 
elevator, as already explained. When the machine is set to 
fly at an increased angle the resistance of th^ wings is 
greater, the angle of attack having been increased so that the 
speed decreases and the machine climbs. When the ma- 
chine is set by the elevator to fly downwards slightly, the 
resistance set up by the wings attacking the air is decreased 
and the machine increases its speed ; so that, if a pilot knows 
at what air speed his machine flies level at a given number 
of engine revolutions per minute, he knows that any increase 
in the air speed must mean that he is flying downwards, and 
that any decrease indicates that he is climbing. If he allows 
the air speed of the machine to drop below the point where 



■V 



12 PRACTICAL FLYING 

sufficient air is dealt with by the planes in a given time to 
maintain the machine in flight — ^i.e., if he allows the machine 
to stall — he will lose control, and only regain it when the 
air speed has again been increased by diving to a point when 
the air dealt with in a given time is sufficient to maintain 
the machine in flight. Before stalling, he will notice a gen- 
eral sloppiness in the controls, indicating the fact that an 
insufficient amount of air is passing the planes and their 
controlling surfaces in a given time to have the desired effect 
on the ailerons, elevator and rudder. He should then imme- 
diately put the nose of his machine down to increase the 
air speed and so regain control. 



Banking and Turning 

It is now necessary to explain that the control lever as 
well as the rudder bar must be moved in the proper direction 
in order to make a turn. If the rudder only were operated, 
the machine would be inclined to skid its comer, as it were, 
and, later on, the nose would go down. It would slip out- 
wards on its turn and would lose speed. To make a gentle 
turn in the air the rudder must be applied, together with the 
correct amount of bank, in the following way : — To make a 
gentle right-hand turn the right rudder is pressed forward 
and the control lever is moved to the right at the same time ; 
to come off a gentle turn the 'control lever is moved across 
in the opposite direction, past the central position — that is 
to the left — and as the machine approaches the horizontal 
again a slight amount of left rudder may be given. Both 
controls are then centred. What happens when an acute 
turn is made will be discussed later in the chapter dealing 
with dual-control instruction. 



The Ailerons 

The pupil can now trace out the wires that connect the 
control column with the ailerons, or controlling flaps, fitted 
to each wing. In some machines there is an aileron, or con- 
trolling surface, to each of the four wings. In others, only 



THE AILERONS 



IS 



the top wings are so fitted. The principle on which the 
ailerons operate is just the same as in the case of the other 
controlling surfaces, i.e., the rudder or elevator. When 
the control lever is moved to the right in order to make the 
machine turn to the right — that is, the right-hand side of the 
machine will be down and the left up— the controlling sur- 
face fitted to the left wing or wings, as the case may be, is 
pulled down. The amount is very slight : the trailing edge 
of the aileron may be, perhaps, half an inch below the trail- 
ing edge of the wing, but the additional resistance set up by 
the extra surface exposed to the air causes that wing to 
rise, while the reverse is the case with the right-hand wing, 




1 



f 



* »i. ' aii. 



1 M  II   w a. - ^ » 



} 



I 



Co<\lirol Uver ^o ri^ht d^^e^ej \eft 
aileron ardi ^atjej "*^ rigVxt^cayjin^ 
n>acVM'ntt ♦© bank f ^o rt\« r^V\V -. 




I* 



- -^ 11 1 1 



'CZZTSTT".:: :::::: :".::::...'. 

Control \«ver ♦o \«fl- dQ\pr9jfer ri^hV 
aileron and raider f t©]|^*" ixtigjCog 
roacVMn* to tank • \ J^ H>€ Sefi . 



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II 
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II 
II 

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The ailerons. The sideways movement of the control lever when 
it is pressed to the right makes the left aileron go down and the 
right aileron come up, which, causes the machine to fly right wing 
down. To make the machine fly left wing down the control lever 
is moved to the left. The sideways movement of the control lever 
is used in banking the machine for turns and in correcting air 
bumps, which cause a wing to rise or drop. 



14. PRACTICAL FLYING 

the aileron of which is connected by a balancing wire to the 
other aileron, and is arranged so that, when the latter is 
drawn down, it is slightly raised, thus helping the right-hand 
wing to become depressed owing to the added resistance on 
the top surface of its aileron, which is now raised' slightly 
beyond its neutral position. On some machines the wings 
themselves are made to move or warp. The control is just 
the same as on the more modem type fitted with ailerons. 

The Engine Control 

Having mastered the details of the control of the machine, 
the pupil can next proceed to discover how the engine is 
controlled. If the engine is a stationary type, as opposed to 
the rotary, he will find his throttle lever and petrol tap not 
much different from those used on motorcars. He will also 
find the ignition switch, which should have its "off" and 
"on" positions clearly marked. In addition, there inay be 
various pumps, the purpose of one of which will befo main- 
tain air pressure in the petrol tank, where the fuel is not 
gravity fed. The pupil should find out which way all the 
taps and levers open and shut, and what are their functions 
and use. He should study the array of strange-looking 
clock- faced instruments and gauges which he will find on the 
instrument board in front of him as he sits in the pilot's seat. 
He will notice the air speed indicator, which gives him his 
speed through the air and not over the ground, except in 
cases where there is no wind ; and also his height indicator, 
which may be graduated in hundreds and thousands of feet. 
The engine revolution counter may be driven direct off the 
engine shaft, in which case it will give him the number of 
revolutions per minute of the engine itself, or off the cam- 
shaft, in which case it gives only half the number of revolu- 
tions per minute performed by the engine. Petrol and oil 
gauges present no novelty to the man who has some motor- 
ing experience; but a compass and sideslip indicator may 
puzzle the pupil to begin with. When the instruments have 
been inspected and their operation explained and under- 
stood, the pupil should find out at what speeds, by instru- 
ments, the machine flies level, glides, and climbs; at what 



ENGINE LIMITATIONS 16 

□umber of revolutions per minute it is safe to run the en- 
gine; how many gallons of petrol and oil the tanks hold; 
how much petrol and oil the machine consumes per hour, 
and, consequently, how long it can remain in the air without 
replenishment. 

Study the Engine 

Next he should turn his attention to the study of the 
ei^ine. If it is one of the stationary type, it may follow 
motorcar practice. The cylinders may be set V fashion, 
with fours pairs of Vs in line, as on tJie Maurice Farman 
elementary training machine, or it may be a fixed engine, 
with the cylinders set radially round the crankshaft, as on 




the Anzani-Caudron, If a pupil is being taught to fly on 
a more highly- developed and complicated engine, such as 
the Gnome, Clerget, or Le Rhone, he must study it with the 
greatest care, and make certain that he understands how to 
operate the throttle and fine adjustment levers without chok- 
ing the engine. The stationary type of engine possesses 
ignition, carburetter and valve gear very similar to those 



16 PRACTICAL FLYING 

employed in motorcar practice. If he does not possess any 
knowledge of the principle on which the petrol engine 
works, he had better at once obtain a reliable handbook on 
the subject, such as the "Motor Manual," and commence a 
study of it without delay, for the more he knows about his 
engine the more valuable will he be to himself and his com- 
rades in after days. » . 



Principles of Aeroplane Construction 

A preliminary study of the machine should include a 
comprehension of the principles on which it is built and 
rigged. The pupil will find that the wings, which carry 
the weight of the machine, consist of main spars and ribs 
braced together by piano wire. Over the whole is stretched 
fabric, which is held in place on the ribs by stitching and 
copper rivets. The fabric is then doped by a special process 
to preserve it from the weather and to tighten it up. Be- 
tween the wings, in the case of a biplane, are the inter-plane 
struts, set vertically. The whole is then braced together in 
cellule form by wires tautened by turnbuckles. The 
weight of the engine, passengers and body of the machine 
in the air is taken by what are called the flying wires, which 
run diagonally from the top plane inwards and downwards 
to the fuselage. The wires leading from the top plane out- 
wards and downwards to the fuselage are called landing 
wires, because they take the weight of the machine when it 
is on the ground. In some machines, the upper and lower 
planes are assembled in one length, in which case the fuse- 
lage, or nacelle, is bolted to the centre section struts and 
rests on the centre of the lower plane. On others, the wings 
are divided into right and left-hand pairs — ^upper and lower 
— ^always taking "right" and "left" as referring to the ma- 
chine when seen from the pilot's seat, and are bolted up to 
the fuselage and centre section. The fuselage of the ma- 
chine is a long, thinly tapered and generally more or less 
rectangular box. At its forward end it accommodates the 
engine, whilst the lower wings are secured to it at each 
side by bolts passing through their front and rear spars. 
The passenger's seat is generally found immediately 



Top : Machine front view, composed of right and left-hand plar 

bolted to the centre section. Bottom: Top and bottom planes 

one unit. A typical fuselage in elevation and plan view. 



. J|3»r-* 





'A(^q|e of lr»cli 



Argle &C lr\ctd«r\ce 







6al»r>ccB ftudder. 



The three top sketches illustrate common aeroplane dimensions, and 
the lower two the difference between a balanced and unbalancd 
rudder. The pupil should familiarise himself with common aero- 
plane terms and their meaning as early as possible. 



THE FUSELAGE 19 

behind the engine, and behind it in turn comes the pilot's 
seat. 



Arrangement of Tanks and Seats 

The passenger's seat has four vertical struts rising from 
the fuselage round it, and above it is the centre section plane 
roughly corresponding with the width of the fuselage. To 
it are attached the upper planes, right and left. From this 
it will be seen that the engine is carried in front of the 
planes, the passenger's seat directly under the centre section 
of the top plane, and the pilot's seat slightly to the rear. 
The fuselage is tapered off to the rear, where the fixed tail 
plane, elevator flap, vertical stabilizing fin (if fitted) and 
rudder are accommodated. The petrol and oil tanks are 
found in the forward end of the fuselage, generally just 
behind and slightly above the engine, although, in some 
cases, a pressure-fed tank is fitted under the passenger's or 
pilot's seat. Generally speaking, however, the aim of the 
designer is to centre all the weight as much as possible, so 
as to secure ease of manoeuvring. The whole of the weight 
of the machine on the ground is supported by the under 
chassis, or undercarriage, fitted under the fuselage and mid- 
way between the main planes. The undercarriage is at- 
tached to the wheels and axle of the machine, through the 
medium of some form of shock absorber, such as the San- 
dow elastfc, so as to decrease the shock of landing, or "taxy- 
ing" over rough ground, as much as possible. A tail skid 
fitted at the rear of the machine serves the same purpose in 
relation to the tail, which would otherwise drag along the 
ground until fl3nng speed was obtained and might seriously 
strain both itself and the rear part of the fuselage. 

Further practical knowledge may be gained by the pupil 
if he is able to spend some time in the erecting and engine 
shops. He will learn how to cover a plane with fabric, how 
to dope it, how to true up a machine that is nose or tail 
heavy, or flying with one wing down. Simple work, such 
as wire splicing, making loops and eyes in piano wires, and 
the correct method of fitting Sandow shock absorbers to 
the landing wheels, is all easily learnt, and will certainly be 



PRACTICAL FLYING 



I 



Principles of aeroplane construction. Constructional details of an 
aeroplane. Top: What a wing looks like when the fabric is re- 
moved. Bottom : A typical undercarriage with double pairs of 
landing wheels and arrangement of skids. 

of great value to the potential aviator at some period of his 
career. At the same time it is quite possible to become a 
first-rate pilot without a great deal of technical knowledge, 
just as many people can drive cars or motorcycles well 
without knowing much about their working. Other things 
being equal, however, the man who knows most about the 
practical and mechanical side of his machine and engine 
will be more valuable than the man who knows little or 
nothing. 



CHAPTER III 
Elementary Principles of Aeroplane Engines 

IN school flying, one of the principal troubles to be 
guarded against is engine failure. Not that this is so 
frequent as it was in the early days, for aeroplane en- 
gines are very much more reliable now and are very much 
better understood, but the necessity for studying the en- 
gine and its peculiarities and of obtaining a good working 
knowledge of it cannot be too strongly impressed upon the 
pupil. It may save quite a lot of trouble and very possibly 
some forced landings. 

While learning to fly, the pupil should take a personal in- 
terest in the engines and machines he has to handle, and if 
at any time any trouble is experienced with an engine simi- 
lar to his he should endeavour to find out the reason and 
the remedy. He should acquire such practical knowledge 
as whether it is safe or advisable to continue flying with 
one or two cylinders misfiring; what black smoke belching 
out of the exhaust pipe signifies ; why certain machines are 
difficult to start up in cold weather, and how this failing can 
be remedied; how much petrol and oil the tanks hold, and 
how much fuel the machine uses per hour ; and the causes 
and cures for the hundred and one little troubles that will 
crop up from time to time during his course at the flying 
school. 

The Four-stroke Principle 

Practically all aeroplane engines, as in motorcar prac- 
tice, work on what is known as the four-stroke principle. 
Any handbook on the petrol engine, such as the "Motor 
Manual," explains this detail, but a rough outline of the 
working of a four-cycle engine may be given. Imagine a 
cast-iron jar turned upside down with a close-fitting, but 

21 



88 PRACTICAL FLYING 

shorter, iron jar, also inverted free to slide inside it. Fixed 
to the inside of the inner jar is a rod, which is enlarged and 
hollowed out at its lower end so as to fit over a crank. Car- 
rying the simile still farther, at the top of the larger jar are 
two doors which can be opened and closed by a suitable 
mechanism at the desired moment, from which lead two 
pipes, one to the carburetter or device in which the petrol 
and air are mixed in the desired proportions so as to form 
an explosive mixture, and the other to the silencer, or ex- 
haust expansion chamber, from which the burnt gases can 
issue into the air. The door, or valve, to which the car- 
buretter pipe leads, is called the inlet valve, and the door, 
or valve, opening into the exhaust pipe, is called the exhaust 
valve. 

Engine Parts 

There is also a machine called the magneto, capable of 
supplying an electric spark at the correct moment in the 
space between the top of the shorter jar and the under side 
of the top of the largest jar This space is generally known 
as the combustion chamber, while the larger jar represents 
the cylinder and the inner and smaller one the piston. The 
rod from the piston to the driving shaft is called the con- 
necting rod, and the shaft is, of course, the crankshaft, to 
one end of which the propeller itself can be fitted. Both 
the valves are opened at the correct moment by a system of 
gear wheels, driven off the crankshaft and cams, which 
lift the tappet rods and rocker arms in contact with the 
valve stems, but they are closed by springs, called the ex- 
haust valve spring, in the case of the exhaust valve, and the 
inlet valve spring, in the case of the inlet valve. The 
magneto is also driven by the engine, and sends an electric 
current along a rubber insulate^ wire to the sparking plug, 
which is screwed into the combustion chamber with its 
sparking points inside, and its insulated terminal, to which 
is attached the cable from the magneto, on the outside of 
the cylinder. 

The cycle of operations is divided into four strokes of the 
piston. The first is the suction stroke, with a downward 
movement of the piston; the second is the compression 



ENGINE PRINCIPLES 



23 



stroke, with an upward movement of the piston ; the third is 
the explosion or power stroke, with a downward movement ; 
and the fourth is the exhaust stroke, with an upward move- 
ment of the piston again. After the four strokes have taken 
place, the series starts again, and as each up and down 
stroke of the piston represents one revolution of the crank- 
shaft, which may be doing from 1200 to 2000 revolutions 
per minute, it can easily be understood that the strokes f ol- 



imd- >alve o^ 



® 



ir^du€tion 
Stroke . 



find ^ 
both yJh\>/tj 



® 



Firino 




v*lw« both vdMJ 

® 

^% ? 






IvM^vftWttk^ 



® 

ExhMosV 
Stvckc 




Diagrammatical illustration of the principle of ^e four-stroke en- 
gine, showing the cycle of operation. 



low each other with extraordinary rapidity. It will also be 
noted that only one stroke in four is a power stroke, and 
therefore the engine has only one power stroke to every two 
revolutions of the crankshaft. Thus, if the engine were run- 
ning at 1200 revs, per minute (usually expressed as r.p.m.), 
it would mean that only 600 power strokes, or explosions, 
were taking place every minute. 

Having grasped the cycle of operations, the pupil must 



^ 



S4 PRACTICAL FLYING 

next familiarize himself with the working of an engine in 
greater detail. The piston in the course of its movements 
up and down inside the cylinder never reaches the closed top 
of the cylinder; there is always a small space, called the 
combustion space, left between the top of the piston at the 
upward limit of its travel and the under side of the top of 
the cylinder. 

How Power is Developed 

When the piston descends on the first stroke the inlet 
valve opens and the explosive mixture is sucked into the 
combustion chamber from the carburetter by way of the 
inlet pipe by the displacement caused by the downward 
travel of the piston. The inlet valve is then closed by the 
action of its spring, and as the exhaust valve remains closed 
during the first three strokes of the cycle of operations, the 
combustion chamber is sealed gas tight. The piston then 
ascends and compresses the mixture already received into 
one-fourth or one-fifth of the space it originally occupied. 
When the piston is at the top of the second (compression) 
stroke the magneto is so timed that it sends an electric cur- 
rent along the rubber insulated wire to the sparking plug 
points inside the cylinder, when the spark takes place and 
fires or explodes the compressed mixture. This explosion 
drives the piston down on its third, or power, stroke and 
imparts energy via the connecting rod to the crankshaft of 
the engine. On the last stroke of the cycle of four the ex- 
haust valve opens and the piston in its upward course drives 
the burnt and used gases before it, past the exhaust valve 
into the expansion chamber and exhaust pipe. When the 
piston has reached the top of its travel it has driven out 
most of the used gases. The exhaust valve closes and the 
cycle of operations commences again, with a downward 
travel of the piston and the opening of the inlet valve. In 
passing it may be noted that a gas-tight joint is made be- 
tween the piston and the inner walls of the cylinder by 
means of piston rings, which fit in grooves in the piston and 
tend to spring out against the walls of the cylinder. 



VALVE OPERATION 25 

Valve Systems of Aviation Engines 

This cycle of operations is common to the great majority 
of aviation school engines, among them being the Renault 
eight-cylinder air-cooled, the Curtiss, and the R.A.F. A 
slightly different systeni is employed in some rotary en* 
gines, notably the Gnome and the Monosoupape. 

In the Gnome engine the mixture is taken into the crank- 
case, and enters the combustion chamber by means oif a 
valve in the head of the piston. This valve is worked auto- 
matically, and so does not need a system of timing gears, 
cams, tappets and rocker arms to operate it. The valve is 
caused to open by the suction in the combustion chamber on 
the intake stroke, and a spring returns it to its seating when 
the piston ascends again to compress the mixture. The ex- 
haust valve is operated in the ordinary manner and is car- 
ried in the head of the cylinder. See sketch of this valve 
arrangement on page 28. 

The Monosoupape, or single valve^ engine works on the 
four-stroke principle, but only employs one valve, which is 
carried in the cylinder head as in the Gnome. This valve is 
open to the air, and on the inlet stroke allows air only to 
enter the cylinder. It closes, however, some time before the 
piston reaches the bottom of its travel, or stroke, so that 
suction is set up inside the cylinder while the piston is still 
descending. There are passages connecting the crankcase 
and the combustion chamber, and as a very rich mixture has 
already been prepared in the crankcase it rushes into the 
combustion chamber, owing to the suction already present 
there, as soon as the piston uncovers the passage ports on 
its downward path. The upward stroke of the piston com- 
presses the mixture of pure air from outside the engine and 
very rich mixture from the crankcase in the ordinary man- 
ner, and, as in the previous example, the third stroke, i.e., a 
downward movement of the piston, provides the power as 
the mixture is fired at the top of the stroke. On the fourth 
stroke, the valve opens again and allows burnt and used 
gases to pass out into the air; then the cycle commences 
once more, the valve remaining open, as already explained. 



«6 PRACTICAL FLYING 

to allow pure air to enter the engine during the first half of 
the downward inlet stroke. 



One Principle, Man; Types 

From this very elementary description of the principles 
on which the petrol engine works the pupil may have some 
difficulty in recognizing the various parts when confronted 
with a modem aeroplane engine. He will find, however. 



RotVi) Cnguw 



jWhw) 



Four ^es of aeroplane engines. 

that if he has a sound idea of the fundamental principles of 
the working of a single-cylinder motorcycle engine, and if 
he can take it to bits and put it together again he will soon 
pick up the peculiarities of the more complicated aviation 
engine. Perhaps the arrangement of the cylinders on the 
crankcase may strike him as unusual, or it may be that the 
position of the valves or methods of driving the camshaft 



TYPES OF ENGINES 27 

puzzle him. But familiarity with the first principles will 
soon show how they work. 
Aeroplane engines may be classified as follows : — 

Stationary Engines 

Cylinders arranged in line Example: — i6o h.p. Beard- 
vertically as in motorcar. more, six-cylinder, verti- 

Cylinders arranged in V for- cal. 

mation. Example: — 80 h.p. Renault 

or 90 h.p. R.A.F., eight 
cylinders in two sets of 
four, set in the form of 
a V. 

Cylinders arranged radially. Example : — 100 h.p. An- 

zani, cylinders set radi- 
ally round the crankshaft. 

Rotary Engines 

The cylinders rotate round a Example : — 80 h.p. Gnome ; 
fixed crankshaft. 80 h.p. Le Rhone ; 100 h.p. 

Monosoupape ; 1 10 h.p. 
Qerget. 

The arrangement of the valves in these engines varies. 
The commonest practice is to fit the overhead type ; on the 
80 h.p. Renault and the 90 h.p. R.A.F. the exhaust valves 
are of the overhead type and the inlet valves are placed 
under them. The camshaft is carried between the cylin- 
ders at the bottom of the V and lifts the valves by tappets. 
On the Curtiss, both valves are overhead; on the Gnome, 
the inlet valve is, as already described, situated in the piston, 
and is of the automatic, or atmospheric, type. The exhaust 
valve is carried in the cylinder head, and is driven by cams 
and tappet rods. On the Monosoupape, the overhead valve 
serves both as exhaust and air intake valve. On the Le 
Rhone and Clerget engines, both inlet and exhaust valves 
are carried in the cylinder head, and are operated by means 
of tappets. Some diflferent valve arrangements are illus- 
trated. 



S8 



PRACTICAL FLYING 




Mftch»nic»UM o^raHd cxh»uft va\v^ 



C^ltn^r 



VftWe. 





CMttoder 



m\cV 




/ 



rich mwtMr« 

vaWc Monojou|^J>e 




•If 



Arrangement of inlet and exhaust valves on aeroplane engines. Top 
left: The super-imposed arrangement. Bottom left: Overhead 
inlet and exhaust. Centre : Gnome pattern inlet in piston, and over- 
head exhaust. Right: Monosoupape or single-valve engine. 

Generally speaking, the rotary engine is lighter per pound 
per horse-power than the stationary type. Rotary engines 
are all air cooled, whilst only the smaller stationary engines 
follow this practice. On the other hand, the rotary engine 
is often more extravagant in petrol and oil consumption 
than the stationary type, and this has to be considered in 
weighing up the relative advantages and failings of each 
type. Generally speaking, rotary engines are used on most 
small and light machines, such as scouts, which are single- 
seaters. On passenger-carrying machines, used for long 
distance work, a stationary engine, generally water cooled, 
is used on account of its reliability and economy. 

It can now be assumed that the pupil has at any rate an 
elementary knowledge of the principles on which the engine 
works, and he desires to pick up as much practical knowl- 
edge about it as he can in the few weeks he has at his dis- 
posal. 



PREVENTING ENGINE FAILURES 



89 



Parts that Give Trouble 

Whenever an engine fails or is being taken down for 
repair the pupil should find out what has happened to it 
and what is being done to remedy it. The parts of an 
engine most liable to give trouble (excluding serious me- 
chanical breakdown) are the sparking plugs, the ignition 
wiring, valves and valve springs, the magneto, the carbu- 
retter, the petrol pipe, the inlet pipe, piston rings, obturator 
rings (wher6 fitted), and the lubrication system. By taking 
these parts one by one and discussing the s)miptoms, causes 
and cures of the troubles, the pupil may learn the kind 
of breakdown to expect, and will see how, by a little care 
on his part, with an occasional inspection of the machine, 
he can prevent many of these failures. 



"ToVDofiCv^ 



\^niVton 




Por¥j d^ed 



••••• IfNlatr c|^A\r. 

•^— 3ucV\or\ 
CrvkVod. 
••■• Cnhfer tvttol 

• Co«rj|pfKriork 



PofVj cVojed 



BoHtM^Ma CcA^rc 



eLF. 



Monosoupape engine timing. Timing diagram of the Monosoupape 
engine, showing how the single valve acts as air inlet and exhaust. 
The rich mixture is admitted from the crankcase by means of trans- 
fer ports in the cylinder walls. 



80 PRACTICAL FLYING 

En^e Troubles, Symptoms, Causes and Cures. 
The Plugs 

Sparking plugs are somewhat apt to become sooted up 
with burnt carbon between the plug points, or with oil get- 
ting up into the body of the plug. In the latter case, the 
plug points may appear clean and yet the plug may be 
faulty. When in doubt, change the plug, and if the cylin- 





TenrMn&t 


5M St>r«2^ 


W^ lyu^iim 






"""~"i 


IT 


P*'^'** 






1 

1 


% 


m 


Nut 




Pl«,T«w«ljJ 










// 




1 






-f-«-' 






r 


V 


V 






If 


1» 


\^ 



der then commences to fire the plug has obviously been the 
cause of the trouble. A new washer should be fitted with 
each plug when it is changed. Sometimes a clean plug 
may be faulty also, so that unless the two plugs have 
been tried do not take it for granted that the trouble is 
elsewhere. Plugs are sometimes capable of being taken 
apart and cleaned with a stiff brush and petrol. The points 
should be cleaned and set the correct distance apart, which 
is approximately i-5oth of an inch. Sometimes, owing to 



PLUG TERMINALS 81 

quick changes of temperature, water will form on the plug 
points and cause misfiring. Sometimes the insulation of 
the plug will be found to have cracked owing to exces- 
sive heat, in which case cleaning is useless and the plug 
must be scrapped. Misfiring may occur owing to the plug 
terminal dropping off through being badly secured. Spring 
terminals, if reliable, are the best, as otherwise a great 
deal of time is wasted in changing plugs. Mechanics 
should carry spare plugs and a plug spanner in their pock- 
ets for the same reason. 

Quick-release Terminals 

Two types of spring terminal are illustrated (page 30). 
The first consists of a piece of bent wire fitted round the 
neck of the plug, with its two ends cranked and sprung 
slightly apart. The insulated wire from the magneto is 
fitted with a copper terminal with a hole in it through 
which the ends of the plug spring terminal are inserted by 
being pressed together. They then spring apart, and there 
is no chance of the insulated wire dropping off the plug, 
although it is only the work of a moment to pinch the ter- 
minal ends together and release them when desired. The 
second type of spring terminal incorporates the high-ten- 
sion lead wire as well, and is used on engines such as 
the Gnome, Clerget and Monosoupape, where there is no 
need to employ a rubber insulated high-tension wire. A 
steel wire is used to convey the current from the distribu- 
ter to the plugs, and incorporates a spring in its design. 
The sketch will explain the idea. To detach the wire it is 
only necessary to take hold of the loop at the end and strain 
the wire against the spring, thus relieving the pressure of 
the upper loop round the groove in the plug. If a plug 
constantly oils up at its points it may be found expedient 
to increase the gap between the points considerably. This, 
however, may make it difficult or impossible to start the 
engine on this cylinder, but it will be possible to start it on 
one of the others, and the cylinder in question will chip in 
when the engine is running. Moisture on the external in- 
sulation of a plug will also cause misfiring, which will 
cease if the plug is dried. 



S2 



PRACTICAL FLYING 



\ 



ir\ 



patrol V^^ • 






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Repairs on the field. Top: How to repair a broken petrol pipe. 
Bottom: A repair to a^ broken or chafed high-tension wire effected 

by means of insulating tape. 



High and Low Tension Wirings 

The ignition wiring does not give so much trouble as do 
the plugs, but it should be examined from time to time to 
see that it is not chafing against any rough parts of metal 
or wood. The insulation material is rubber, and this may 
easily perish if it is constantly subjected to oil or friction 
with some part of the machine. Wiring should be neatly 
clipped up in position by fibre clips, and should not lie in 
long unsupported lengths, as this strains it and may lead to 
breakage owing to vibration. The wiring is divided into 
two systems, the low tension, which requires a thinner 
insulation than the other, which is the high tension. The 
low-tension wiring runs from the low-tension terminal on 
the contact-breaker cover on the magneto to the switch, 
whilst the high-tension wiring runs from the magneto to the 



TYPES OF SWITCHES 



33. 



distributer, and from the high-tension terminals on the 
distributer of the magneto to the sparkir^ plugs. The high- 
tension wiring is generally thicker than the low-tension. 
To repair a chafe in ignition wiring, black insulating tape, 
or ordinary medical tape, can be bound round the weak 
part. If the wiring breaks the insulation can be cut off 
so as to expose the wire core for a short distance. The two 
ends can then be twisted together and the whole joint bound 
with insulating tape. The reason that in some engines, 
notably the Gnome, the high-tension wiring is left free is 
because it is led direct from the magneto to the sparking 
plugs, and so touches nothing en route that would cause a 
short circuit. In this case the air acts as an insulator. 



Switches 

The switches require to be continually looked after to 
see that they are working efficiently. The tumbler type. 




Types of switches. When the switch is "on" the pilot o 
calls out "contact"; in the "off" positjon the phrase used i 
"switch off." 



S4 PRACTICAL FLYINiS 

such as is used in electric lighting installations, is the 
most reliable. The spring button type fitted on the top 
of some control levers is liable to stick at times, and should 
not be depended upon, as the spring is often uncertain in 
action. In this type the switch has to be held down for 
"switch off," and springs on to "contact'' when released. 
All switches are supposed to work in the same direction 
and to be marked for "contact" or "switch off," but this is 
not always the case, and the pupil should make certain that 
he clearly understands how the switch works. In the 
tumbler type the switch springs on to contact easily but 
requires rather more force to put it into the "off" posi- 
tion. 

Valve Troubles 

Valves are subject to many different forms of trouble. 
Generally, it is the exhaust valve which fails and requires 
more attention, because it is subjected to much greater 
heat and strain than the inlet. When a valve breaks off 
at the head the pilot should switch off and land, as other- 
wise there is every chance of the valve head entering the 
combustion chamber and breaking up the engine. The 
symptoms in a broken valve are the sudden misfiring of 
one cylinder, probably accompanied by a sharp metallic 
knocking noise in the exhaust. The cure is to remove 
the broken parts and to fit a new valve. Valves should be 
changed periodically, and an examination made systematic- 
ally will often insure the removal of a valve that would 
break after a few more hours running. If the valve is 
burnt and cracked under the head it should be changed at 
once. Valves also warp, owing to the heat, which means 
that they do not bed down evenly on their seating. This 
makes it impossible to secure a gastight joint. The cure 
is to re-cut or re-grind the valve. Valve grinding is an 
art in itself, and the pupil should familiarize himself with 
the methods employed. The object of valve grinding is to 
make the valve rest evenly on its seat. When the valve has 
been properly ground-in and cleaned up there should be no 
black spots or rings on it or on its seating. Valve grinding 
is done by means of a screwdriver engaged with a groove 



THE MAGNETO 86 

in the head of the valve and a valve-grinding compound. A 
spring is placed under the valve head so as to raise the 
valve from the seating from time to time, and it is bad 
practice to grind the valve without taking this precaution. 
As little of the grinding compound as possible should be 
used, as otherwise the seating will grind into the rings. 
Valves may also stretch, which fault can be watched for by 
noting the clearance between the stem and the rocker arm 
or tappet rod. Stretching is often a forerunner of the 
complete breakage of the valve, and is due to great heat 
or to the valve spring being too strong. Any squeaking 
that manifests itself in the valve guide or rocker arms 
shows that they are dry and that friction is taking place. 
The cure is generally to lubricate them or treat with graph- 
ite. If the valve stem is bent or distorted it will also bind 
in the guide. The cure is to fit a new valve, as straighten- 
ing the old one is difficult and unsatisfactory. It is often 
difficult to fit new valve springs, which have to be com- 
pressed before they can be got into place, but if they are 
first of all compressed in a vice and tied up in position 
they can then be fitted quite easily. 



Ignition Troubles 

The magneto is perhaps too complicated a piece of mech- 
anism for the pupil to take to pieces and repair on the 
field, but a few simple breakdowns which can easily be 
remedied may be described. * Some engines employ two 
magnetos, each firing half of the number of cylinders. If 
one magneto fails, the pilot can soon find out which it is 
by feeling which cylinders are cold and then tracing the 
high-tension wiring from the cold cylinders to the faulty 
magneto. To test for a faulty magneto, leave the switch 
on, put one cylinder in the firing position and rock the 
propeller gently to and fro. Feel the high-tension terminal 
of the plug, and if no shock is experienced it proves that 
the magneto is at fault. The greatest enemy to the efficient 
working of a magneto is oil and dirt. Therefore, very 
often, merely cleaning up the magneto will cure the trou- 
ble. The distributer should be free from oil (which it 



PRACTICAL FLYING 







A complete magneto con- 
tact breaker (left), and 
details of the make and 
break (right). 



very seldom is on rotary engines), the contact breaker 
should be clean, and the high-tension terminals and brushes 
should be cleansed carefully to get rid of any lubricant 
which has crept in. The brushes should work freely in 
their guides or holders, and their springs should be strong 
enough to ensure efficient working. Frequently, trouble is 
encountered in connection with the contact breaker. The 
platinum points may require cleaning, trimming and adjust- 
ing to their correct clearance or else, especially in damp 
weather,, it may be found that the rocker arm, which oper- 
ates against a cam and opens the points, has seized. The 
cure is to ease it in its bush and vaseline the metal pivot. 
This trouble may either cause total or partial misfiring, 
the latter being by far the more difficult to detect. Broken 
brushes cause total misfiring, while dirty distributers or 
contact breakers are frequently indicated by partial or in- 
termittent misfiring or difficulty in starting. Sometimes, in 
damp weather, moisture condenses inside the magneto and 
causes partial and erratic firing. To cure this trouble, the 
magneto should be taken to pieces and the armature and 
magnets dried in a warm room. See that a bar of iron 
connects the two ends of the magneto, as they may lose 
their magnetism. Moisture on the high-tension terminals 
will also cause misfiring, which will disappear if the termi- 
nal is dried. 



CARBURATION 37 

Failure in Petrol Supply 
Carburetter troubles are mostly experienced in connection 
with the jet, which every pupil should be able to remove. 
A "jet key should be part of every pilot's tool kit, as it is 
often impossible to remove the jet with the ordinary type of 
spanner. Popping and uneven firing indicate partial re- 
striction in the supply of petrol. This may take place at 
the jet, where the flow of petrol from tank to engine is 
naturally most restricted, in any of the small petrol pas- 
sages of the carburetter, or in the petrol pipe, filter, or 
petrol tap itself. AH kinds of dirt seem to find their way 



To illustrate carburetter design. (A) Main jet. (B) Compensating 
jet. (C and D) Slow-running jet and choke tube. (E) Air inlet. 
(P) Set screw holding compensator. (C and G') Screw caps betow 



88 PRACTICAL FLYING 

into the carburetter from time to time, and it is a mystery 
where they all come from. Cotton wool, grit, bits of rub- 
ber from petrol joints or composition piping would all 
cause stoppage. If a failure of the petrol supply is sus- 
pected and the tanks are full, the first thing to do is to 
turn on the petrol and flood the carburetter. The petrol 
should then pour out; if it does not, the petrol union 
should be disconnected at the carburetter and the flow 
tested again. If it is good the fault is in the carburetter. 
If bad, the trouble lies in the pipe, filter or tap. Should 
the carburetter be assumed to be at fault, remove the jet, 
see that it is clean and blow down it. Clean out the 
float chamber with a cloth and petrol, re-assemble the parts, 
and test the carburetter again. In cases where the pipe 
supply is restricted, take Ae pipe oflF from the tank and 
blow down it until it is free. If the pipe is not blocked, 
turn on the petrol tap at the tank and watch the flow. If 
It is poor, clean out the tap and tank, for the root of the 
trouble lies there. In the same way the filter should be 
tested and the gauze thoroughly cleaned. Specially made 
petrol pipes of composition often perish after a time, and 
should therefore be renewed before they disintegrate and 
cause choking. Petrol pipes should never be unsupported 
for more than short lengths as the vibration of the engine 
will cause fracture. A rubber joint is often inserted in a 
long length of piping to overcome this risk. 

Repairing a Broken Petrol Pipe 

To repair a broken pipe rubber tubing can be slipped 
over the adjacent broken ends, which are then bound up 
with copper wire and insulating tape. A punctured float 
will also cause trouble in the carburetter. This can be 
detected by removing the float and shaking it. If there is 
petrol inside, fit a new float and return the other to the 
mechanics, who will heat it, thus vaporizing the petrol, 
which will emerge in bubble form if the float is immersed 
in water, and thus indicate the position of the puncture. 
The float can then be soldered up and made air-tight again, 
if care is taken that the addition of the solder does not 
weight it and so upset the level of the petrol in the jet. 



GNOME ENGINE CARBURATION 89 

The correct mixture is indicated by a perfectly-running 
engine, and if misfiring occurs when the ignition is correct 
it will indicate too rich or too weak a mixture. Black 
smoke from the exhaust indicates too much petrol, as does 
a long yellow flame. Too rich a mixture may be due to 
flooding of the carburetter at the jet, or shows that the 
air valve is stuck and remains closed. A restricted supply 
of petrol or air leaks in the carburetter or induction pipes, 
will result in too weak a mixture being formed. In winter, 
larger jets are often used than would be necessary in the 
summer. In cold weather it is possible to facilitate starting 
by heating the carburetter and inlet pipes with a hot rag 
to assist vaporization. 

Difficulty in Starting 

The main air ports to the carburetter may also have 
to be closed during induction in order to prepare a very 
rich mixture for starting up. If the engine and carbu- 
retter are water jacketed, hot water can be poured into 
the radiator, and this will materially assist in starting the 
engine. Sometimes, although the petrol may have been 
filtered through gauze or chamois leather, water will be 
found in the jet and float chamber. Unless it is removed 
misfiring will occur. Petrol or oil funnels and filler caps 
should never be left on the ground, as they pick up dirt, 
which will probably enter the petrol and oil tanks and 
cause trouble. On an engine such as the Gnome, where 
no float chamber is fitted, these remarks apropos float 
chamber troubles obviously do not apply. In this latter 
type of engine the only thing that can go wrong is a petrol 
jet situated in an inlet pipe through which air is taken into 
the crankcase. The regulation of the petrol supply, which 
is by hand instead of by float, is, however, a much more 
difficult matter. Sometimes the air control lever or throttle 
wire may break and cause the engine to stop. If the return 
springs of these levers are set to keep the throttle and 
air valves open in case of failure of the engine controls, 
this trouble will be overcome. 

Inlet pipes can only cause trouble by cracking at their 
joints or breaking away at the unions. In either case the 



42 PRACTICAL FLYING 

with the tail down. Sometimes, in order to warm up this 
type of engine more effectively, the tail is jacked up to a 
height of several feet while the machine is in the flying 
position. The oil will then be distributed evenly throughout 
the crankcaae and will reach the pistons and bearings more 
quickly. In any case it is advisable to warm up the engine 
gradually and slowly from cold, and never to run it at 
maximum revolutions for longer than is absolutely neces- 
sary. This applies not only when testing the engine on the 
ground, but also when flying. Very seldom, except in 
climbing, is full engine power desired or needed. Level 
flying can be carried out on most machines with the engine 
running at several hundred revolutions below its maxi- 
mum. 

Common Engine Failures 

Should the engine stop suddenly the cause will be failure 
of ignition or of the fuel supply. To cure it, test the 
magneto and switch, and then the petrol supply. 

The misfiring of one cylinder will probably be due to a 
faulty plug. If the misfiring is accompanied by a loud 
banging, or rattling, the cause is probably a broken valve. 

If one set of cylinders misfires the reason may be put 
down to magneto failure. 

If irregular or infrequent misfiring occurs it will be 
because the rocker arm on the magneto contact breaker 
sticks occasionally, or because there is oil or dirt on the 
distributer, or the platinum points require trimming. 

Misfiring, accompanied by spluttering, is brought about 
by an insufficient supply of petrol or the air valve sticking. 

Difficulty in starting the engine may be due to the cold 
weather, or the fact that the plug points are set too far 
apart. The magneto contact breaker or distributer may re- 
quire cleaning, or there may be an air leak in the induction 
pipe. If the engine runs well when it has once been started 
the last cause may be suspected, as the mixture might be 
too weak for starting but correct for general speed. 

Black smoke from the exhaust may be the result of too 
rich a mixture, or show that the carburetter is flooded, or 
an air valve stuck in the closed position. 



ENGINE FAULTS 4d 



Run a New Engine Gently 

Should the number of engine revolutions drop after it 
has been run for some time, without misfiring, partial 
seizing up of bearings or pistons has probably occurred, as 
the result of either faulty lubrication or lack of play in the 
parts concerned. This is likely to occur on a new or re- 
cently overhauled engine. Great care should therefore be 
taken during the first few hours flight of a new engine in 
order to allow the bearings and other parts to run in. If 
the steel cylinders are blued, or discoloured, the obturator 
ring may be suspected, if one is fitted. In passing, it 
may be mentioned that an obturator ring is a special form 
of piston ring used on rotary engines in conjunction with 
the ordinary type of ring. It is made of brass, and is 
L shaped, with the ordinary piston ring between the piston 
and the downward stroke of the L. It is necessary owing 
to the uneven cooling of the rotary engine, the front of the 
cylinders receiving all the cooling draughts. 

If the engine runs well for a few seconds, then splut- 
ters and continues to run, the cause may be a partially 
choked jet or water in the petrol. 

Bad vibration of the engine is generally due to the mis- 
firing of one cylinder, but it may also be caused by a loose 
propeller, or the engine being loose in the engine bearers. 
Sometimes the propeller is faulty, and this causes the engine 
to vibrate, in which case it should be changed at once. A 
small chip out of a propeller will upset its balance and will 
affect the smooth running of the engine. 

General Hints on Running an Engine 

Always warm it up slowly and gradually. 

Never run it at full power, in the air or on the ground, 
for longer than is absolutely necessary. 

Use as little petrol and throttle opening as is possible 
in accordance with flying conditions. 

Remember that in case of engine failure it is always 
safer to make a landing with some cylinders firing than 
tp continue until the whole engine gives up. 



i- 



f 

I 



44 PRACTICAL FLYING 

<\ 
Listen to the sound of the engine andr try and detect 

fauhs before they become serious. 

Never open the throttle suddenly, as it^ strains the en- 
gine. . 

Run the engine on the chocks as little ias possible, and 
on rotary engines do not use the "blip" switch more often 
than is necessary, as the life of an engin^^s greatly cur- 
tailed by non-observance of these rules, ^r 

Have the engine thoroughly overhauled, J at the regular 
intervals arranged for it. •' 

On long cross-country flights ease the engine from time 
to time by throttling down or gliding. ' * 

Never go up without testing the engine^ and never go 
up with a misfiring or unsatisfactory engine. Have any 
trouble put right on the ground. 



! 



I 

i 



> 

V 



'i 



CHAPTER IV 

irhe First Lesson in the Air 

PRIOR to deceiving the first practical instructions in 
flying th(^ pupil should realize that he cannot learn 
too much* about the theory of flying and the means 
of controlling a^n aeroplane before he actually finds himself 
in the pilot's «eat ready for his first lesson. He will 
learn very miiiph more quickly if he has had already a 
preliminary grounding in the rudiments of mechanical flight 
than if he star^ without a notion as to how or why a ma- 
chine flies. Bpth instructor and pupil, therefore, will save 
themselves a good deal of time and trouble if the former 
explains to the latter the elementary principles of flight 
before attemptihg to instruct him upon handling a machine 
in the air. Enjphasis should be laid on the particular im- 
portance of the method of controlling the machine and 
the mistakes to be guarded against in the air. 

^ Dual-control Instruction 

The method ;now almost universal of teaching pupils to 
fly is by mean^ of dual-control machines. In the early days, 
after having acquired a theoretical knowledge of an aero- 
plane and the method of controlling it, the pupil was sent 
off for rolling practice, or "taxying," on an under-pow- 
ered machine, which could not possibly leave the ground. 
The next stage was to give him a machine with a wing 
surface sufficiently large just to allow him to get off the 
ground for short hops. From this he would advance to a 
machine which 'would just fly, upon which he would make 
"straights" until he was proficient, later on attempting turns 
on a more powerful machine. 

This method has been superseded at all Service schools 
in favour of dual-control instruction. This means that the 

45 



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The duplicate controls of a dual-control machine. On different types 
of machines the seating accommodation is arranged in different ' 
ways. Sometimes the pilot sits in front and the pupil behind, and 

vice versa. 

46 



HEIGHT TO FLY 47 

machine is provided with two sets of rudder and control 
levers, one to be worked by the ^pil, who generally sits 
behind, and the other by the instructor. On some ma- 
chines one set of control levers is used, but they are placed 
in such a way that the instructor can work them by reach- 
ing over the pupil's shoulders. It is probably best for the 
pupil to be put in the pilot's seat from the beginning and 
for a telephone or speaking tube to be arranged between 
him and the instructor. 



Communication in the Air 

It is a great advantage if some means of communication 
be installed between the pupil and his instructor. A system 
of speaking tubes may be fitted or signs may be arranged. 
By this method a great deal of verbal instruction can be 
given in the air and the effect of the control movements 
demonstrated. This method obviously saves a great deal of 
time. If the instructor's position permits — as, for instance, 
if he were reaching over the pupil's shoulders in order to 
handle the controls — he may be able to speak to the pupil 
in the air without the need of a speaking tube. 

Opinions are divided as to what is the best method and 
machine for teaching pupils. Some instructors prefer a 
"pusher" type, whilst others think that time is saved by 
taking a pupil on a "tractor" type from the beginning. In 
any case, the school machine should not be too fast or 
too sensitive on the control. 



Working the Controls 

There are many different methods of instructing, and 
it will generally be found advisable for the first lesson in 
the air for the instructor to take the pupil up to a calm 
and safe height, say looo ft. or 2000 ft., and then allow 
him to feel the controls. It is here that the importance 
will be appreciated of the pupil knowing what he ought 
to do before he has actually the chance of doing it. He 
should not be frightened of working the controls and no- 




The tractor type of aeroplane with the propeller and engine in 
front of the machine. Note the long tapering body or fuselage 
terminating in the tail. The tractor type of aeroplane is now em 
ployed Dractically universally the old t>pe pusher machine having 
been superseded even in school work. 



^ ., ._ ... ... : with the propeller behind the pilot 

Note the pilors seat in the nacelle in front of the planes and the 

tail booms and open frame work in place of the fuselage on the 

tractor type. 



80 PHACTICAL FLYING 

ticing the effect they have on the machine. The instructor 
may allow him to get into an unusual position and then 
show him how easy it is to get out of it. It is far better 
for the pupil to acquire the feel of the machine as quickly 
as possible than to sit still and watch the instructor do 
the work. 

Flying Straight 

The first lesson is to learn how to fly the machine straight. 
Not only must the pupil fly in a straight line towards some 
point which he selects in front of him, but he must fly the 
machine level, i. e., neither upwards nor downwards. He 
must fly laterally'level, and not with one wing up and the 
other down. He will find that, to begin with, he is tmable 



Flying straight. How to fly straight by selecting some prominent 

object on the horizon, such as a church, and steering the machine 
to it with the rudder. Another good method of flying straight is 
to steer the machine along a straight stretch of road or railway, or 
to 6y it parallel with these landmarks. The machine is kept straight 
by means of the rudder. 



FLYING LEVEL 61 

to control the machine in these three directions at once. He 
can get the directional straightness with the aid of the 
rudder bar, but he may allow the machine to roll sideways, 
or see-saw. On some machines it is necessary to keep on 
a certain amount of rudder in order to make them fly 
straight, and the pupil should realise that if he finds the 
machine drifting away to one side from the point he has 
chosen he should rudder in the opposite direction, and, if 
necessary, keep the rudder on. 

Flying Level 

In learning to fly level, i. e., neither climbing nor de- 
scending, the horizon should be watched and also the trim 
of the machine generally when it is set by the instructor in 
the correct position. The pupil can then attempt to keep 
the machine in that position by moving his control lever 
forward to prevent the machine climbing, or backward to 
prevent it descending. If he knows the correct flying 
level speed of the machine, he can also watch his air speed 
indicator. He must remember that any increase in its 
speed (with the engine running at its normal number of 
revolutions) means that the machine is descending, and that 
any decrease in speed indicates that the machine is climb- 
ing. It is also necessary to bear in mind the fact that 
the air speed indicator is sluggish in action and only regis- 
ters a change in speed after the machine has made that 
change. It should be borne in mind also that, if he is 
high, he will never come to any harm by allowing the 
machine to go too fast ; whereas, on the other hand, he can 
easily allpw the machine to get into an awkward position 
through permitting the speed to drop below flying speed, for 
it is the relative speed between the planes and the air 
that preserves the machine in equilibrium. 

Horizontal Level 

To keep the machine horizontally level it is necessary 
to watch the horizon and to attempt to maintain the front 
elevator (if there is one — or if the machine is a tractor, 
the wings) parallel with the horizon. This will only be 



keeping the underside of the top plane parallel with the horizon. 
the pupil notices that one wing is down, he must move the control 
lever sideways in the opposite direction to pull it up, and then 
centre the lever. 



In flying level on the Ijaurice Farman school machine, the front 
elevator is trimmed parallel with the horizon. This type of machine, 
which at one time was largely used for school work, has now been 
superseded by the tractor type. It is commonly known as the Long 
Horn, as opposed to the Short Horn, Maurice, which had no 
front elevator. 




64 PRACTICAL FLYING 

attained by practice, and the pupil should not be disheart- 
ened if he does not pick it up at once. When he notices 
that one wing is down, he should move his control lever in 
the opposite direction to that wing until the machine is 
flying horizontally again, whereupon he can move his lever 
back to the neutral position In working any of the con- 
trols, it must be remembered to operate them gently, grad- 
ually and firmly. On no account should they be jerked or 
moved quickly. 

Bumps in the Air 

Every now and then what are termed "bumps" in the 
air are felt. These may affect the fore-and-aft or lateral 
level of the machine, and they must be corrected as they 
occur. The amount of correction necessary will only be 
found by practice. If a bump puts the front of the machine 
up, the pupil must move the control lever forward, and 
when flying level again he can centre his control. If, on 
the other hand, a bump sends one wing up, the lever must 
be moved sideways toward the wing that is up, in 
order to allow the other wing to rise; then, when he is 
level, he again centres his control. On some machines 
lateral bumps can be corrected by working the rudder in 
conjunction with the control lever. To do this he must 
rudder into the bump and work his control lever in the 
same direction. Thus, if a bump sends the right-hand wing 
up or the left-hand wing down, whichever way he likes to 
take it, the pupil must warp to the right with his control 
lever and rudder to the right also. When he is level again 
he moves his control and rudder into the central position 
as before. 

Turning 

« 

The next stage, probably, will be to make a turn. This 
is quite simple. It is wise to begin a turn with a slight in- 
crease of speed, if the machine has a small range of speed. 
Both the rudder and warp, or the control lever, are then 
moved i^ently and simultaneously in the direction in which 
it is desired to turn, the right foot being pressed on the rud- 



BANKED TURNS 55 

der to turn right, and the control lever moved to the right 
to pull up the left wing. The machine will bank gently 
and come round quite easily. Once the correct amount of 
bank is on, the lever can be centred. When the turn is 
completed the rudder and bank are taken off again, by mov- 
ing the lever in the opposite direction, following up with op- 
posite rudder and then moving the control and rudder to 
their neutral positions. If the rudder is moved in the oppo- 
site direction too soon, the nose will go up and the machine 
will slip inwards. The controls must not be centred again 
until the machine is laterally level. This method applies 
in general to gentle turns. 

Before going on to describe how to do steep turns, the 
pupil must grasp the action that the elevator and rudder 
have on the machine. When the machine is flying level 
and straight, a backward movement of the control lever 
will always cause the nose of the machine to attempt to 
reach the tail, and in doing this the nose will go up above 
the horizon. The application of right or left rudder will, 
in the same way, always tend to make the nose of the 
machine try to turn to the right or left wing tip, so that, 
when the machine is flying level, the rudder causes the 
machine to turn, while the backward or forward movement 
of the control lever causes the machine to climb or de- 
scend, or fly level, as compared with the horizon. 

Inversion of Controls 

Now consider what happens when the machine is made to 
execute a vertical banked turn and is on its side relative 
to the horizon. Take the case of a left turn. If left rudder 
is held on when the machine is on its side in the turn, it 
will cause the nose to approach the left wing, as in the 
previous case, but, judging the position of the machine 
from the point of view of the horizon, it will cause the 
nose to drop below the horizon. Right rudder will have 
the opposite effect, i. e., it will make the nose of the ma- 
chine try to approach the right wing, which is uppermost : 
in other words, comparing the nose again with the horizon, 
right rudder will make the nose go up. 

Next, take the action of the elevator when the machine 



56 


PRACTICAL FLYING 




mm.. 






«!..'-«• 




n. 



Illustrating the inversion of the controls on a vertical turn. 



is on its side in a steep turn. If the control lever be pulled 
back, it will cause the nose of the machine to try to approach 
the tail, but as the machine is on its side, in relationship to 
the horizon, this backward movement of the stick will 
simply speed up the turn and make the machine turn more 
quickly. So that if the nose of the machine is still com- 
pared with the horizon, it is found that on a vertical bank 
the nose is trimmed above or below the horizon by the 
use of the rudder and the machine made to turn by the 
use of the control lever which operates the elevator. At 
turns of 45 degrees, the rudder acts half as rudder and 
half as elevator, and the elevator acts half as rudder and 
half as elevator. At lesser angles the elevator is more 
elevator than rudder, and the rudder more rudder than 
elevator, when the nose of the machine is compared with the 
horizon, whilst at steeper angles of turn the elevator be- 
comes more and more the rudder, and the rudder more 
and more the elevator. 

Now to describe the method of making a steep turn, the 
control movements for which the pupil, having mastered the 



STEEP TURNS 



57 



idea outlined in the preceding paragraph, will not find at 
all difficult to understand. To make a steep turn to the 
right (or left), bank and rudder are applied in the desired 
directions; in this case to the right, until the machine is 
more or less on its side. Then the nose of the machine 
is trimmed to the horizon by means of the rudder, right 
rudder bringing the nose down and left rudder bringing it 
up. It will be found necessary to ease off the right rudder 
while the stick is then pulled back so as to make the ma- 
chine turn. While the stick is pulled back, it will be found 



Rudder 


"^ 


^ 




 > ^, 






^ 




=^ ^ 


"T"^ 


L«ver • 




5^ 


vi 




> 


® 




<D 

PLAN 


(D 

VIEW 




® 




© 




® 


® 




Ruddv ebr.....c: 


, -_ 


rra ^** 


f^ 




^ 




^ c^ 




CmMi Le^mt- 


■-■h 




if> 


• 





Movements of the rudder and control lever on a steep left-hand 
turn (plan view), (i) Control lever and rudder in neutral or cen- 
tral position. (2) Left rudder and left control lever — machine takes 
up bank. (3) Rudder eased off to trim the nose of the machine to 
the horizon, and control lever brought back to make the machine 
turn. (4) Rudder eased off still more if necessary, and the control 
lever brought to opposite side and fully back to prevent overbank- 
ing. (s) Coming out of the turn — control lever moved over to the 
right first. (6) Then, as the machine approaches the horizon, the 
control lever can be moved forward and right rudder applied. (7) 
When the machine is approaching the horizontal both levers are 

moved centrally. 



68 PRACTICAL FLYING 

that the bank of the machine is inclined to get steeper and 
steeper owing to the increased speed and consequent lift 
imparted to the left wing by its controlling aileron which 
is down, so that it is then necessary to ease off the bank 
slightly ; that is, the stick, besides being pulled back to speed 
up and make the machine turn, must be moved towards the 
opposite side, viz., to the left. Once the correct position 
of the levers has been found the machine will continue 
to turn round and round without losing height or increasing 
its bank or radius of turn. To get out of the turn, oppo- 
site bank is used; that is, the stick is moved to the left, 
and, when the machine is approaching its horizontal and 
lateral level again, left rudder must be applied and the 
stick can then be moved forward again to its central posi- 
tion. Gliding and climbing turns are made in exactly the 
same manner, except that, in the former case, the nose of 
the machine must be trimmed below the horizon, and in the 
latter above the horizon, the amount below or above the 
horizon depending on the speed and rate of descent or 
ascent required. 

Learning to Land 

In passing, it may be noted that there is no need for the 
pupil to hold the controls as tightly as he can, or to jam 
the rudder with his feet. A machine can be controlled with 
one hand holding the control lever quite lightly; in the 
same way, the rudder can be operated by a mere touch of 
the toe. 

When the pupil can fly the machine correctly in the air, 
he will be taught to land and get off. Many instructors 
give landing practice by flying round and round in circles 
and landing once in each circuit. This method is all right 
if the machine is brought to a standstill after each landing, 
and a few words of advice are given to the pupil as to the 
mistakes he made in his previous get off and landing. An 
instructor can teach a pupil as much, if not more, by talk- 
ing to him and taking him into his confidence than by going 
on flying for hours without verbal instructions. The per- 
sonality of a pupil should be studied if the best results are 
to be obtained from him. In giving landing and getting-off 



GETTING OFF 69 

instructions, the faults made on the previous circuit should 
be explained. If a pupil does not understand why the ma- 
chine behaved in such and such manner when he last landed 
or got off, he should ask the instructor the reason. The 
instructor would also be well advised to ask the pupil at 
the end of each flight if he has any questions. Even if he 
has not, a few words may be given in explanation of any 
point that has arisen whilst in the air. All this shows the 
advantage of some means of communication being arranged 
between pupil and pilot if the flying lessons are to be con- 
cluded with the greatest expediency. 

It may be pointed out that, to begin with, short flights 
of ID to 15 minutes duration are of more value to the 
pupil, who easily becomes tired until he gains experi- 
ence, than longer flights of from 30 to 60 minutes. 

Getting Off and Landing 

In getting off, a pupil must accelerate the machine grad- 
ually, keeping it straight towards some point by means of 
the rudder, and when it has attained its flying speed pull 
back the control lever or elevator very gently. Generally, 
when the machine is just in the air, he should ease the lever 
forward momentarily to allow the machine to gather more 
speed. He can then continue his climb with a margin of 
safety in hand for emergencies. 

In landing, the pupil first cuts off the engine, puts the 
machine at the correct gliding angle by moving the con- 
trol lever forward, then, on approaching the ground, which 
he must watch intently 20 or 30 yards ahead of him, he 
pulls the lever back slowly until he has flattened out a 
foot or two above the ground. If he holds the lever still, 
the machine will slowly sink as it loses its flying speed 
and touch the ground quite slowly and without any jar. 
In landing, it may be necessary, owing to bumps or mis- 
judgment, to ease the control lever forward or to hold it 
for a moment, but the general tendency will be a back- 
ward one. 

Some further notes on getting off and landing will be 
found in the chapter which deals with the pupil's first solo 
flight. 



60 PRACTICAL FLYING 

When to Make a Solo Flight 

The moment when a pupil is ready to go solo is a 
point of importance both to him and to the instructor. 
The latter has the responsibility of a possible accident if 
the pupil is sent up too soon; while the pupil has his 
own neck to consider and the damage he may do to an 
expensive machine by making a bad landing, or commit- 
ting some other error, which ends in an accident, through 
being over-confident or too keen to go solo. The time a 
pupil takes to learn depends on the type of machine upon 
which he is taught, his capabilities, and also the instructor. 
Some men learn to fly in 2 hours; some take as long as 10 
or 12 hours. 

An instructor should also ask the pupil if he feels con- 
fident and would like to go up solo. If the reply is in the 
negative, then, generally, more instruction must be given. 
The pupil must have confidence in his ability to handle 
the machine before he goes up alone, which will be increased 
if he has already gained a certain amount of faith in his 
instructor as a judge of his own capabilities. 

Before a pupil is allowed to go up alone he should be 
able to land, take a machine oflf the ground and fly it in the 
air for six short circuits without the instructor touching the 
controls. 

If the pupil feels confident, and the instructor is satisfied 
as to his capabilities, he should go up solo, preferably on 
the identical machine on which he has been instructed. To 
put the pupil in another machine, where, perhaps, the in- 
struments are placed differently, and where the adjust- 
ment of the machine may be different, even though it is of 
the same make, is to handicap him. Again, to teach a pupil 
in the front seat of a two-seater and then to send him up 
solo in the back seat, or vice versa, is to take a risk which 
is quite unnecessary, for the positions of the pupil and in- 
structor can easily be changed on most dual-control ma- 
chines. A pupil is thus given every chance of making a 
good first flight. He should be sent off, if possible, with 
little or no warning, in order that he may be caught with his 
blood up, as, for instance, immediately after an instructional 



ADVANCED INSTRUCTION 61 

flight. Some pupils are most imaginative, and if they have 
no time to ponder over the possibilities of their first solo 
flight, they take the air much more readily and confidently. 
The first flight should be on a calm day, preferably when 
there are no other machines in the air. Exact instructions 
as to where to fly and the length of the flight should have 
been received beforehand. Generally, four circuits and 
landings are enough for the first solo. The pupil should 
have been taught at what height, and over what landmark, 
he should, switch off in order to land at the desired spot in 
the aerodrome. Having satisfied himself that the machine 
is in proper condition, the instructor will do well to with- 
draw so as to let the pupil get into the air without any 
nervousness that may be caused by the thought that the in- 
structor is watching him. 



Instruction on Advanced Types 

When a pupil can fly one type of machine really well 
there is little need for a great deal of further instruction 
on the more advanced types. For this reason it is better to 
keep a pupil on one type of machine for several hours 
until he can fly it really well than to send him up on other 
kinds of machines, none of which he has had time to fly 
properly. Given sufficient room on the aerodrome for fast 
landings, a man who can fly one type of machine well should 
be able to fly most others with tolerable success. He will 
only master special peculiarities of different types of ma- 
chines by experience. Probably he will notice that the 
speed and sensitiveness of the controls are the chief points 
of difference. 

A great advance has been made recently in dual-control 
machines, some fast machines having dual control nowa- 
days. There is, therefore, no need to take unnecessary risks 
by sending pupils up solo straight away on these machines. 
It is better to work up from slow and sluggish machines 
to fast and sensitive ones, with a little preliminary dual 
control on each. It is only the landing and getting off that 
require attention, and half-an-hour's instruction on these 
points should be sufficient. The pupil should remember. 



7 



68 PRACTICAL FLYING 



however, that he is not entitled to as much instruction on 
the more-advanced types of machines as when he was learn- 
ing to fly. In the early days, when there were only one or 
two types of dual-control machines available, as soon as 
pupils could fly them they had to go on to the more- 
advanced types without any instruction whatever. 



CHAPTER V 
The First Solo Flight and Aerodrome Practice 

BEFORE starting on a flight, whether the first solo 
or a 200 miles cross-country journey, it is a wise 
plan for a pilot to look over his engine and machine 
methodically. He should not take it for granted that the 
machine is ready to fly because the mechanic reports it so, 
but must look over it himself. Some pilots have the me- 
chanical instinct born in them; others have not, and will 
never attain it. The latter are the people who are in the 
habit of using pliers to undo nuts, or who employ wood 
chisels in the place of a screwdriver. 

Attention to the Engine 

First glance over the engine, which is the more impor- 
tant part; and here a thorough knowledge of aero engines 
will be of great value. The following are some of the 
details that should be examined: — The terminals on the 
sparking plugs and the magnetos should be tight ; both the 
high and low-tension wiring should be neatly clipped up 
and not lying about the machine in festoons, which might 
tend eventually to chafe through and cause a short circuit 
(at any points where wiring touches the metal portions of 
the machine, some form of additional insulator, such as 
insulating rubber tape or a fibre ring, should be inserted) ; 
the petrol unions should be tight; rubber connections, if 
fitted, must not be perished ; and if the petrol pipe is made 
of some woven material it should be examined for signs 
of disintegration. Tappets and rocker arms should be in- 
spected, and both should be properly lubricated. It should 
be noticed if any split pins are missing, and that those 
that are fitted are not loose. If automatic inlet valves are 
used, the pupil should see that they are working properly. 

63 



64 PRACTICAL FLYING 

Finally, the pilot should be satisfied that there are no petrol 
or oil leaks, and that the switch is working properly. 



Overlooking the Machine 

Next, the machine itself must have some attention. After 
some hours flying experience on one type of machine, the 
pilot will know which parts are most liable to give trouble. 
These may be the wires slacking oflf in the tail, or the tail 
itself may be liable to work loose. Wear should be looked 
for in the Sandbw shock absorbers in the under-carriage, 
or perhaps on an aileron which is inclined to bind. Loose 
or missing nuts and bolts should be looked for. The turn- 
buckles should be correctly locked and the control wire 
pulleys or guides greased properly. They should work 
easily without too much slack in the wires. Of course, the 
controls are most important, the most vital being the eleva- 
tor control. They must be tested by sitting in the machine, 
working the control lever and rudder bar, and, at the same 
time, observing if their operation has the desired eflfect on 
the ailerons and tail. If the wires show signs of chafing 
where they pass over the pulleys, they should be changed. 
In some machines it is possible for the mechanics after an 
overhaul to connect the elevator control \yires in the wrong 
way, i. e., they may forget to cross them. It is thus neces- 
sary to pay particular attention to the machine after it has 
been in the shops or when the controls have been over- 
hauled. The nuts and bolts and the locking arrangements 
for securing the landing chassis wheels should be inspected 
occasionally. 

Preliminary Engine Tests 

Whilst sitting in the machine the pilot should test the 
engine and see if it is developing its proper number of rev- 
olutions ; if not it requires attention. This is an important 
detail, because a slight falling-oif in engine revolutions 
means a very great reduction of the power developed. At 
the same time, it should be remembered that an engine will 
often give 50 or 100 more revolutions per minute in the 



ENGINE TESTS 66 

air than it does on the ground, and this must be allowed for. 
A skilled pilot can tell, of course, by the sound of his 
engine whether it is missing fire or running unevenly or 
weakly. He should then switch off and tell the mechanics 
to feel the cylinders, the cold one being that causing the 
trouble. A partial misfire is always more difficult to locate 
than a total misfire. The latter must be due to one of two 
things — either a choked or broken pipe, or faulty ignition 
at the magneto or switch. 



Knowledge of the Engine 

Too much importance cannot be attached to the need for 
the pilot to understand his engine and machine perfectly. 
When he knows his engine well, and has the feel of the 
machine, he can tell exactly how it is flying, and what is 
more, he can often discern faults in the machine or the 
engine before they become really serious. If his engine 
fails, he should be able, after some hours flying, to diagnose 
the trouble before he comes to earth, just in the same way 
as a good motorcar driver can tell what has caused his 
engine to stop before the road wheels of his car have come 
to rest. 

In warming-up an engine it is wise, when cold, to open it 
up slowly, in order to allow the metal to expand 
evenly and to permit the oil to thin and circulate 
properly through the bearings before full power is applied. 
In cold weather a longer period must be given for warming- 
up than in summer time, when the oil is not congealed. In 
very cold weather the castor oil used on many machines 
will solidify almost to the condition of candle grease. To 
thin it, methylated spirit may be mixed with it in the propor- 
tion of one pint to a gallon of oil ; petrol can also be mixed 
with the oil in the proportion of i in 20. 

The pilot should remember that the oil supply must be 
turned on before starting the engine, otherwise it will 
seize up very soon. On a rotary engine he must note the 
rise and fall of the oil contained in the pulsator glass domes. 
If these pulsations show up, he can take it that the oil pump 
is working and the oil supply turned on. 



66 PRACTICAL FLYING 

( 

Starting Up 

The engine and machine having been tested, the pupil 
is now ready to start. It should be noted that the onus ' 
of accidents occurring when starting up the engine by 
swinging the propeller rests with the pilot. Incidentally, I 
the mechanic should always treat the propeller as if the i 
engine were "on contact," and, for this .reason, it is a good I 
plan for the switch to be fitted on the outside of the ma- I 
chine where the mechanic can see it. ' 

When ready to suck the mixture into the cylinders, the ' 
mechanic shouts "Switch offl" or "Suck in!" whereupon 
the pilot, first looking to see that the switch is oft (it 
should have the "On" and "Off" positions clearly marked), 
replies, "Switch off." The mechanic then sucks in until 



The importance of wind. The air speed of the machine is relative 
to the air, and not to the ground. If the whole atmosphere is 
moving at lo m.pii., and the machine air speed through the air is 
40 m.p.h., the speed of the machine over the ground will be 50 m.p.h. 
Against the wind the ground speed will he 30 m.p.h. Hence the 
importance of getting off and landing against the wind. 



THE SWITCH 



67 







Starting up without chocks. Men holding back the machine and 
keeping the tail down while the engine is tested. 

immediately ready to start the engine, when he shouts, ''Con- 
tact !" The pilot switches on and shouts, "Contact 1" The 
mechanic then bumps the propeller over compression and 
the engine should start. The words "contact" and "switch 
off" are chosen so that there shall be no doubt as to what 
is meant, as there might be if the words "switch off'* and 
"switch on" were used instead. Both mechanic and pilot 
should see that they speak distinctly and loudly. The 
switch must always be left off except when it is desired to 
start the engine. The importance of this can be realised 
when it is mentioned that a man's arm or wrist can be 
broken easily by the premature firing of the engine. 



Importance of Wind 

When starting, the pupil must remember to face the wind, 
and the same remark applies to landing. In both cases this 
is done in order to reduce the speed at which the machine 



68 PRACTICAL FLYING 

leaves or lands on the ground. For Instance, if there be a 
lo-mile-an-hour wind blowing, and the fowest flying speed 
of the machine is 40 miles an hour, by facing the wind the 
pupil can leave the ground and land at 40 minus 10, which 
equals 30 miles an hour. If, on the other hand, he starts 
and lands with the wind, he must do so at 40 plus 10, 
which equals 50 m.p.h., so that, in this case, it is seen 
there is a difference in the ground speed of getting off 
and landing of 20 miles an hour — a very considerable item 
when it is remembered it may be necessary to land in a 
small field where a limited space is allowed for the '*run,'' 
or "carry," after the landing. 



Signals to Mechanics 

The usual method of signifying to the mechanics that 
the pupil is ready to get off is to wave the hand above 
the head, whereupon they will withdraw the chocks from 
under the wheels. When the chocks are withdrawn, the 
pupil will do well to see that all the mechanics are standing 
clear. It happens sometimes that one of them, possibly 
holding down the tail, has not seen the signal, and he or 
his clothing may easily become entangled in the machine if 
the pupil went off unexpectedly, ^here is another point 
which the pupil must guard against, and that is the possibil- 
ity of the chocks being withdrawn in mistake before he is 
ready, or, alternatively, in a mechanic starting up the engine 
without first seeing that the chocks are in position. If the 
pupil were not already warned against these possibilities, 
he might easily run over the mechanic, owing to the forward 
rush of the machine, through the throttle being too wide 
open, or, in the case of a rotary type of engine, which 
cannot be throttled down so well as a stationary one, 
through keeping the switch on too long. 

Having satisfied himself on these points, the pupil should 
make certain that he has a clear run in front of him and 
that there are no other machines in the neighbourhood, 
either getting off or landing, which can possibly baulk 
him. This applies especially to machines which might be 
landing over his head. If he has to taxi out some *dis- 



starting 



GETTlWa OFF 



Ut off 



Gaihcnno yo^So* 







In M>e air 



Mo^ flying JP^'^* OinMr^ ^M^ 



M 



V^ 



PlyicNo level 



5«*itcK off. T ^^ 1 



LANDINQ 






■ii 






9lait dF fWki^ out 

fkUcnir^ out. 



Lai>diKQ . f^iv^ioq along 




Getting off and landing. The movements of the control lever are 
indicated by the white line on the fuselage (exaggerated). It is of 
the greatest importance, both in getting off and landing, for the 
pupil to look ahead, so as to have some mark in view by which he 
can keep the machine straight. 60 



PRACTICAL FLYING 




tance in order to get into the wind, he should make certain 
thit he allows himself ample room in order to clear such 
obstacles as woods, trees, or sheds. 

Getting Off 

Now comes one of the two more difficult parts of a 
pupil's initial flying experience — the start. It is a good plan 
to get under way slowly and to open up the engine gently. 
thus gathering speed gradually. Then, if the machine should 
tend to swing sideways it can be counteracted by rud- 
dering in the opposite direction before the sideways swing 
develops into anything serious. A machine may swing 
sideways when starting for a variety of reasons. Some- 
times it is due to the pupil, who is often liable to over- 
rudder on the ground until the machine is edging in the 
desired direction. This causes it to swing sideways fur- 



GETTmG UNDER WAY 



ProteHc rejult 


\ 




"-'••' 



Getting of! with the tail too low and without sufficient flying speed. 

Unless the control lever is immediately put forward, the machine 

will stall and crash, 

ther than intended. The rudder should be eased off as 
soon as the machine starts to swing in the required direc- 
tion. This appHes more particularly to fast machines. 
Another possible reason for a machine swinging is that 
the pupil, in opening the throttle, which is placed on one 
side, may allow his foot to act automatically in conjunc- 
tion with his hand, i. e., if he opens the throttle with the 
left hand he may push his left foot forward at the same 
time. When in doubt, it is a good plan to switch off 
altogether and to make a fresh start, unless the machine is 
already in the air. 

Engine Economy 

It is desirable to get under way gradually. This saves 
the machine, which should at all times be treated as a 
fragile and very sensitive piece of mechanism. It is well, 



72 PRACTICAL FLYING 

also, to throttle down the engine a little in the air, for it 
is never a good plan to run it ''all out" at any time. 

On a long flight it pays to throttle down the engine every 
now and then and to glide down a thousand feet. 

The pupil starts by moving his stick forward slightly as 
he gains speed, and by getting his tail well up, but not 
too high, for, if on a tractor, the propeller might hit the 
ground, gathering speed gradually and slowly and almost 
imperceptibly pulling the control lever towards him. When 
he feels the machine in the air he can ease the control lever 
forward momentarily in order to allow the aeroplane to 
pick up speed. The speed will then increase, but the rate 
of climb will decrease. Generally, it is wise for a pupil 
not to climb the machine at its lowest flying speed, but 
rather to allow three or four miles an hour for possible 
mistakes. The use of the instruments which indicate the 
speed of the machine is described in Chapter VI. 

Turning 

It is a bad plan at any time to turn near the ground be- 
cause there is little air space in which to correct bumps, side- 
slips, or any other unexpected occurrences. It is wise, 
therefore, for the novice to keep straight on his course 
against the wind until he has attained a height of 500 to 
1000 ft. ; then he can make his turn. 

When turning on school machines, where there is gen- 
erally not a very wide range of flying speed or reserve of 
engine power, the nose of the machine should generally be 
put down slightly and the turn should be made at or 
slightly over flying level speed. Some instructors consider 
that the stronger the wind the more must the speed be kept 
up in turning. The reason for this, they say, is that in all 
turns a machine is inclined to lose height, and especially 
is this the case when turning down wind. Many pilots 
imagine that in turning down wind they experience a curious 
sloppy feeling in the controls, whereas they seem to detect 
a much firmer grip of the air when turning up wind. Much 
discussion and argument have taken place on this subject, 
but theoretically,, at any rate, it should make no difference to 
the control of a machine whether it be turning up wind or 



TURNING 



^s 



down wind. How many pilots, for instance, could detect 
an up wind or down wind turn, if they could not see the 
ground, as would be the case if they were flying above 
the clouds? It is wise not to rely too implicitly at any 
time on the air speed indicator. This is specially true 
when turning, the danger lying in the possibility of the 
pupil holding off the bank when turning down wind near 




^COW*"^ 



Aiir jpeed mdicdtor -K^ 
on ihe left wing . 




4p. 



If the air-speed indicator is fitted to the left wing, on a right- 
hand turn it will register more than the mean speed of the ma- 
chine. On a left-hand turn it will register less than the mean speed 

of the machine. 

the ground, more particularly with stable machines. As- 
suming that the air speed indicator is fitted in the vicinity 
of one, say, the left-hand, wing tip, as is the case on most 
tractors, then, in making a turn to the right, the left-hand 
wing is obviously travelling much faster than the right- 
hand one. Therefore the air speed indicator tube attached 
to the left wing is over-registering the mean speed of the 
machine. On the other hand, if a left-hand turn is to be 
made, the indicator is under-registering the mean speed. On 



PRACTICAL FLYING 




Incorrect turns, showing how sideslips occur. 

tractor machines the air speed indicator is fixed to one side 
of the fore-and-aft centre line of the machine in order that 
it may not be interfered with by the slip stream of the pro- 
peller, which is driven out past the fuselage of the machine. 
In pusher machines, the air speed indicator tube is fitted 
centrally. 

Straightening Up 

In turning, a pupil should put his nose down slightly by 
moving the control lever forward. He should then push the 
rudder and control lever over together in the direction he 
desires to turn. When he wishes to fly straight again, he 
brings the rudder and the control lever back to the cen- 
tral position, or, in some machines, slightly over in the 
opposite direction, the opposite bank being applied first and 
the opposite rudder applied as the machine approaches a 
horizontal position : the quicker the turn the more rudder 
and bank are required. The controls are centred when the 



AT 1000 FEET 



76 



machine is level. He should never turn slowly, as this 
manoeuvre may result in a sideslip and stall, which means 
that the machine loses its flying speed and gets into a tail- 
down or cabre position. 



The First Flight Solo 

The pupil has now attained the height of looo ft. or 
so and is flying down wind. He is comparatively happy, 
as, once in the air at a fair height, the control of the 
machine is a simple matter. There are, however, several 
pitfalls into which he may tumble if he is not careful. He 
must always have in the back of his mind the possibility 
of an engine failure necessitating what is known as a 
forced landing. With this in view, he should always, so 
far as is possible, be able to turn into the wind and land 
in the aerodrome. Consequently, pupils who fly low over 
woods, houses, or other obstacles are taking unnecessary 
and foolish risks. If any useful purpose were to be served 



Mo. 



Lzknd Here — .. 



El' 
El! 
G' 






^o no^ \arwd VNerc 



i! 



LAndtnaTc 



l>\VecV40n o4 ujtrkdi 






ill? - 

,.Bf 



Lar\ci Kere 



=x 



T>o r\o\ V^ndl Kere 



Gi 



H^n q^r 



y. 




^-^ 



eK 



The landing ground of an aerodrome, showing where and where 
not to land. The same thing applies equally in getting off. 



76 



PRACTICAL FLYING 



by running such risks, then by all means let him take them ; 
but otherwise such flying is unjustifiable and extremely 
foolish. A pupil should remember that it is only given to 
the average pilot to make two or three such mistakes in the 
. air before meeting with a really serious crash, attended by 
broken limbs, or perhaps worse. 

For the same reason it is a bad plan to point the machine 
towards woods, trees, hedges or buildings unless the pupil 
is absolutely certain that there is sufficient space to prevent 
him from running into them in the case of an engine failure 
when starting, or to attain sufficient height first to enable 
him to turn round and land on suitable ground. In land- 
ing, too, he should allow himself as much room as possible 
for the run of the machine and should not head it towards 
obstacles, as he is likely to overshoot the mark consider- 
ably. 

Flying Over Bad Ground 

In certain circumstances, as, for instance, in the case of 
a cross-country flight in misty weather, when it is impos- 



I 




The rule of the air when overtaking or meeting another aeroplane. 



RULE OF THE AIR 






Points to notice when encountering another machine in the air, i.e., 

avoid flying or landing in the backwash of another machine, as the 

air in the wake of the machine is very bumpy. 

sible to fly high, it may be necessary to fiy low in the 
vicinity of woods or other unfavourable landing ground. 
Where possible, these grounds should be flown round, if 
they are of great extent, instead of over them, as an engine 
failure, with the ensuing forced landing in a forest, is not 
an undertaking that a pilot relishes, although such landings 
have been made in exceptional circumstances without the 
pilot suffering so much as a scratch. 

The Rule of the Air 

Whilst in the air a sharp look-out should be kept for other 
machines. This applies to all kinds of flying, but is par- 
ticularly true at flying schools, where there is generally a 
large number of machines in a comparatively restricted air 
space. Usually, some set course is laid down, i. e., right 
or left-hand circuits, and pupils should familiarize them- 



78 PRACTICAL FLYING 

selves with the course to be adopted before going up. In 
the air, the "rule of the road/' as laid down by the Rojral 
Aero Club, is that one keeps to the right when meeting 
machines and steers clear when overtaking. When ma- 
chines meet at an angle the pilot that finds the other ma- 
chine on his right must steer clear. In fljring near other 
machines, a pupil may encounter bumps set up by the 
propeller of the other machine, but these need not alarm 
him, as it is a simple matter to correct or avoid them. 
For the same reason it is not advisable for a pupil to 
land behind another machine, as its wash may upset him 
considerably. In flying near airships he should beware of 
trailing wires. In fact it is well to avoid flying in the 
vicinity of these craft. 

;^ /',,,. . Discomfort of Bumps 

Ji^*' . . . 

During their early flying experiences many pupils are 

apt to become alarmed at the bumps they find in the air. 
To begin with, these bumps may certainly seem strange 
and uncomfortable, but, in reality, a pilot with a good ma- 
chine is absolutely safe in them. In flying, it is a question 
of the higher the fewer, and quite often a pupil may find 
that the first 500 ft. or 1000 ft. of atmosphere are bumpy, 
but at anything above that height the air is quite calm. 
Bumps have been known to occur at heights of 10,000 ft. 
or more, but this is very exceptional. It should be remem- 
bered that a bump under a wing will only put a machine 
into such a position as it frequently assumes when turning 
even at quite moderate banks. Bumps will often be found 
in the region of clouds, and sometimes, too, they may 
herald the approach of a thunderstorm. 

Sometimes it happens that a pupil, on his first or second 
solo flight, may lose himself, in which case he has only 
himself to blame for not studying the lie of the land whilst 
under dual-control instruction. He should remember, how- ' 
ever, that a machine flown solo will rise much more quickly 
than when two persons are carried, as in dual-control work, 
and, therefore, it behooves him to keep an eye on the height 
indicator or aneroid, and see that he does not get higher 
than he has previously been accustomed to. Again, it is 



LANDING 79 

inadvisable for him on his first solo flight to venture into 
the clouds, where he may easily get lost. He should also 
remember that, when flying down wind, he will cover the 
ground very much more quickly than when flying against the 
wind, which is another fact that may cause him to lose 
his bearings on his initial flight. 

Landing 

There is now only the landing to be considered. The 
pupil knows already that he has to land against the wind, 
and not facing obstacles, such as woods or hangars. More- 
over, he must not land over such obstacles, as they may 
easily put him off his straight glide to earth, which is the 
best kind of landing for him to attempt at present. He 
should know approximately at what height and at what posi- 
tion over the ground he should switch off or throttle down 
his engine in order to hit off the point on which he intends 
to land, and on reaching this position he should throttle 
down his engine fully. On most machines the throttle is 
set when closed so as to allow the engine to tick over at 
200 or 300 revolutions per minute. He must put the nose 
of the machine down firmly and gradually until the desired 
gliding angle and speed are attained (this is generally 
about the average flying speed), and then watch the ground 
carefully. If there be other machines on the ground which 
baulk him, it is a wise plan to switch on and to make an- 
other circuit while the ground clears. If he overshoots his 
mark, owing to faulty judgment, or if he sees that he is 
going to undershoot, it is a good plan to make another cir- 
cuit, so as to give himself the best possible chance of 
effecting a good landing. In the latter case he could, of 
course, switch on his engine, and having gained the neces- 
sary distance by flying level in place of gliding, throttle 
down again, but this may put him off his glide and upset 
his calculations. 

Assuming that he sees that he will hit off the landing 
ground correctly, he must watch the earth most intently, 
keeping up his correct glide, angle and speed all the while. 
When he gets within 20 ft. or 30 ft. of the earth he can begin 
almost imperceptibly to flatten out by manipulating the con- 



80 



PRACTICAL FLYING 



trol lever in just the same way as that in which he took 
the machine off the ground a few minutes before. Still 
watching the ground intently about 20 yds. or 30 yds., or 
even more, in front of the machine, he continues to pull back 
the lever ever so gently until he gradually decreases his 
flying angle, and, finally, as the machine loses its flying 
speed, its angle of descent is blended in the horizontal of 
the ground without the slightest jerk, and the machine 




If the pilot makes a fast landing and pulls the stick back too 
quickly in order to get his tail on the ground, he will balloon, as 
shown in the upper illustration. If he makes a slow landing, he will 
be far more likely to land safely, even on bad ground. The lower 
illustration shows what happens when a machine, landing fast, 
strikes a ridge or uneven part of ground. 

comes to earth. In easing back the control lever, it may 
be necessary at times to pause momentarily, or even to move 
the stick forward slightly, if the backward movement has 
been made too suddenly, or too much, and has resulted in 
the machine being unduly held up, or even made to "bal- 
loon." The whole art of landing consists in accurately tim- 



LANDING PRACTICE 81 

• 

ing the relative position of the ground and the machine by 
the eye working in perfect unison with the hand. The rea- 
son why the pilot must look ahead to land, and not directly 
beneath him, can be explained by reference to the fact that 
in a fast travelling railway train single sleepers on the track 
can be seen if the observer looks ahead out of the window, 
whereas if he looks down beneath him the sleepers pass 
him in a continuous blur. So in landing; the further one 
looks ahead the slower the ground appears to be travelling, 
and vice versa. 

A pupil must remember from his earliest flying experience 
that he must put the nose of the machine down if for any 
reason the engine stops or slows. Generally speaking, he 
will come to no harm through going too fast in the air, 
which simply means that he is going downwards ; but he will 
easily get into difficulties if he tries to fly too slowly, which 
means that he is trying to climb the machine at an angle 
so great that there is not sufficient speed of air under 
the wings to maintain them in flight. He must also remem- 
ber the importance of keeping the machine heading perfectly 
straight in the direction in which it is intended to land (this 
direction being determined at a height of several hundred 
feet above the ground), and of not allowing it to swing 
out of its course, either owing to bumps or to the necessity 
of having to use more engine. 

Land on a Mark 

No pupil can expect to make a perfect landing at the 
first, nor yet the second attempt. It is all a matter of 
practise, and the best way to obtain proficiency is to prac- 
tise landings. He can also practise landing on one par- 
ticular spot in the aerodrome. By flying in a big aero- 
drome he is all too apt to allow the machine to land where 
it wants to, instead of making it land where he wants it. 
This tendency, should be strenuously avoided, and the pupil, 
especially when he becomes more proficient in the use of 
"S" turns, should always fix on some definite spot on the 
ground where he intends to land, and then make his machine 
land as near that spot as possible. To begin with, he should 
not make his "S" turns too near the ground, but as he 



8S 



PRACTICAL FLYING 



becomes more proficient he can turn lower and lower, al- 
ways remembering that if he has plenty of speed on the 
machine he will also have plenty of control over it. The 
reverse is equally true. 



Landing Mishaps 

) There are two alternative faults in landing, one very 
much worse because it is more dangerous than the other. 



Qlidinq in . 



FtaUcning out 




1 




• .v^rwK . fl^vrw.'*  



ff 



Gliding 



•n 



F&ilurc to 
fUltcn out. 








•I 



Bad landings. "Pancaking," result of flattening out too high; and 
the effect of omitting to flatten out, or flattening out too late. 

A pupil can either fail to flatten out and thus fly into the 
ground, in which case he probably smashes his machine 
in landing by turning it over; or he flattens out too much 
or too early. In the latter case a "pancake," or, if it be 
between lo ft. and 20 ft., a ''stall" results. A pancake 
means that the machine lands, several feet up in the air 
instead of on the ground, and then, having lost its flying 
speed, it pancake^, or drops to tarth. If the pancake is not 



"PANCAKING'' 



83 



very pronounced, no damage may be done, as the elastic 
shock absorbers on the under-carriage will take up a great 
deal of it. 

When the machine has once landed the pilot should allow 
the tail to drop on to the ground of its own accord. He 
must not pull it back onto the ground, for if this is done 
the machine will often leave the ground again for a height 



Gli<iir\o in 






foo UVc 



^ 




iK., 



bounce. 



...*' 



Sto^-naarly m dt>ch. 



IbucK ground Kerc. 



60•>pV^ 



^ 




Lo«9 



run, 



•U 



ij^ ?.hpr». 



rsjrs 



louch oround Ktre. 



50 m p h 

......^ 



^ir 



Preventing a bad landing by putting on the engine after bouncing. 
Fast and slow landings and their ultimate effect on the "carry" of 

the machine. 

of several feet. In some machines the tail is purposely 
held up off the ground as long as possible. 

A worse variety of pancake will result in a broken under- 
carriage, but no other damage to machine or pupil. The 
worst form of pancake, which takes place when the ma- 
chine loses its flying speed at a height of 20 ft. to 30 ft., 
often develops into a stall, which means that the machine 
loses its flying speed in mid-air, followed probably by a 
sideslip, when the machine crashes down on one wing and 
is hopelessly smashed. In Ais case the pupil may be hurt, 



84 PRACTICAL FLYING 

although, if the height is not great, he may not be seriously 
injured, as the wings act as a cushion to the blow by 
breaking up and thus absorbing the shock. The only meth- 
od of saving such a catastrophe is to put the nose of the 
machine down to allow it to regain its flying speed, or else 
put on the engine and so allow it to pull the machine out of 
its precarious position: both these operations could only 
be performed by experts, as the air space is generally too 
small to allow of this evolution being performed suc- 
cessfully. An expert would get the machine to earth safely 
by putting the control lever forward and then moving it 
back again instantly; but the operation requires a quick 
touch and an accurate eye if it is to be performed suc- 
cessfully. Pupils should not try such a manoeuvre, as it 
will generally result in their flying into the ground. If the 
engine has failed, they will do better to allow the machine 
to pancake. 

Bouncing and Bumpy Landings 

There is another faulty method of landing, which results 
in the machine leaping or bouncing over the ground, owing 
to its speed being too great when it touches the ground first 
and the angle of descent not being sufficiently small to 
allow it to run along the ground. The best method of coun- 
teracting this fault is to put on the engine slightly between 
the bumps and then to flatten out and attempt to make a 
better landing. This also is by no means an easy operation, 
even for an expert, whose machine may have been made 
to bump unexpectedly by striking a ridge of ground, or 
an unseen bank. If the pupil pulls back the control lever 
too quickly, when the machine still has flying speed, he 
will "balloon," or go up, and had better then put his engine 
on and try again after another circuit. On most machines 
an ideal landing would be to allow tlie tail skid and the 
wheels to touch the ground together. This is called a three- 
point landing and indicates that the machine has been held 
off the ground up to the very last moment. 

In landing, it is always good practice to come down 
slowly and to attempt to strike the ground at the lowest 
possible speed in conjunction with safety. This does not 



TAXYING 86 

mean that it is advisable to glide as slowly as possible, as 
this i3 dangerous practise, and, and if turns be attempted 
on a glide of this kind a stall may result. Instead, it 
means that when the machine is within 15 ft. to 30 ft. of 
the ground the speed may be cut down so that the velocity 
is as low as possible near the ground. The advantage of 
this is that the run, or the carry, of the machine when it 
has once landed is considerably reduced, which assists the 
pilot in making a landing in a small field. If he landed 
very fast his carry would be further, and there would be 
more chance of his running into obstacles or turning over 
if he had to land on soft ground. 

Some pupils, when they see that they are going to over- 
shoot the mark, instead of making another circuit and 
profiting by their previous mistake, attempt to hit off their 
lairding place by bringing the machine down at a much 
steeper angle than its ordinary flying speed. This is a 
common fault and is quite ineffectual, because the ma- 
chine will have gathered so much extra speed on its 
descent that it will lose its flying speed much more slowly 
when flattened out, and will glide across the aerodrome and 
finally run into a hedge or dyke at the other end owing to 
its increased momentum. 

Taxying 

The last point in aerodrome flying, and by no means 
the least important, is the manipulation of the machine in 
taxying. This means driving the machine on the ground 
and steering it with the rudder. Sometimes the ailerons 
are also worked, but in the opposite direction to that adopt- 
ed in the air, i. e., the control lever is moved to the left 
if it is desired to turn the machine to the right; the right 
aileron comes down and acts as an air brake on that side, 
so that the machine turns about that wing tip. Taxying 
should always be done' slowly, especially on bad ground, as 
much damage can be done to a machine by rough or care- 
less handling. 

When it is desired to turn the machine on the ground 
it is sometimes advisable to get up a little speed, raising the 
tail of the machine by putting the control lever forward 



PRACTICAL FLYING 




ConVrel t«v«> y«ruj«Rl (rnjicatsd bij doHial li'na) and 
elfiVAtorr down , n\ecK»ir\icr «t •■cK >uirig Vi^ . 



Taxying down wind. In taxying down wind, keep the control lever 
central or a little in front of central, so that the wind cannot get 
under the elevator and overturn the machine. In landing in a strong 
wind, wait for mechanics to hold down the wings before taxying 
back to the shed. 

and then ruddering in the desired direction. On some ma- 
chines the rudder and tail skids are interconnected, and, in 
consequence, the machine can be steered on the ground with 
the greatest accuracy and ease. If a machine repeatedly 
swings sideways when landed or being taxied, the under- 
carriage is probably out of line with it, and must be trued 
up. When taxying over heavy or rutty ground it is a good 
plan to hold the control !ever well back so as to keep the 
tail of the machine on the ground. When taxying across 
ruts an excessive amount of engine should never be used, 
for if this is done and the tail of the machine be up, there 
is an excellent chance of the whole aeroplane falling over 
on its nose. In windy weather it is sometimes very diffi- 
cult to control the movements of the machine on the 



THE BREVET 87 

ground, in which case it is always advisable to order two 
mechanics to hold the wing tip struts and escort the pilot 
back to the sheds, or out to the starting ground, as the 
case may be. In taxying down wind keep the stick for- 
ward so that the wind cannot get under the elevator, which^ 
is down, and so blow the machine on to its nose. k a v ^ 



/t^' 



Obtaining a Pilot's Certificate ' 

When the pupil has made one or two successful flights 
he may wish to qualify for his pilot's certificate, which 
is issued by the Royal Aero Club of Great Britain and 
Ireland. His instructor will provide him with the neces- 
sary forms, which he has to fill up and forward, together 
with his photograph and the sum of £i is. to the Club 
whereupon his name will be placed upon the list of pilots, 
and he will receive his brevet or ticket, which resembles a 
motorcar license, and is useful to take with him on cross- 
country flights, where it can always be used as a reference 
or proof of identity. The address of the secretary is 3, 
Clifford Street, New Bond Street, London, W. i. 

The test imposed: before the certificate is issued is a 
simple one. The pilot must make two solo flights and 
execute a certain number of figure-of-eight turns in the air. 
He must also land with his engine cut off from a height of 
100 metres, whilst on the first part of the test he must 
land within a certain distance of two marks on the ground. 
It does not follow, however, that because a pupil has taken 
his ticket he is an expert aviator. The ticket flight is the 
simplest possible test, and he still has a long way to go 
before becoming a qualified pilot. The chapters that fol- 
low will show that this is so. 



/} 



J- 



/ 

t •- 



CHAPTER VI 
The Use and Working of the Instruments 

ALTHOUGH It is quite possible to fly well and ac- 
curately without using instruments, they are often 
useful for verifying one's position in the air and 
finding the way across country. 

The instruments generally found on school machines are 
the compass, air speed indicator, height indicator, sideslip 
indicator, fore-and-aft level, engine revolution counter, 
watch, petrol gauge, pulsator glass or sightfeed oil dome, 
and the pressure gauges for the oil and petrol supply. 
There is also the map carrier. These instruments and fit- 
tings should, so far as possible, be grouped together so 
that they can be seen by the pilot with as little deflection 
of his eye from the horizon as possible. Generally, a 
total weight of about 15 lb. or 20 lb. is allowed for the 
complete equipment. 

Illuminating the Instruments 

As the instruments may be used at night, some way of 
illuminating them must be employed. Generally the indi- 
cator fingers and the figures on the dials are painted with 
luminous paint so that they can be seen in the dark. It 
is also quite usual to find a small electric-lighting set with 
battery incorporated in the design of the instrument board, 
with a switchboard for switching on a hooded light to any 
or all of the instruments it is desired to read. Each is 
shielded to prevent the pilot's eyes from being dazzled, and 
can be switched on independently of the others when de- 
sired. 

Some notes on the instruments chiefly used on school ma- 
chines will be of interest. Every endeavour should be 
made to find out not only how they work and how to use 
them, but what failures are likely to occur and how they 
can be most quickly put right. 

88 



THE COMPASS 89 

The Compass 

The magnetic compass is a most important addition to 
any aeroplane intended to be flown across country. It 
should be placed in full view of the pilot in the fore-and- 
aft line of the machine when in the flying position. With 
the tail of the machine raised several feet from the ground, 
the compass should be set perfectly level, both laterally 




The compass. Two typical types of aeroplane compasses. Left : 
The bowl pattern. Right: The vertical type, which is read from 



and fore and aft. The magnetic compass is an instrument 
for indicating the magnetic north, as the red end of the 
magnetized needle to which is attached the compass card 
always points to the magnetic north, unless affected by 
magnetic material near it on the ground or carried in the 
aeroplane. The compass card is pivoted at a point so that 
it is free to revolve in the horizontal plane. To damp out 
vibration it is immersed in a mixture of distilled water and 



90 



PRACTICAL FLYING 



alcohol (two parts alcohol to three parts water) contained 
in a kind of bowl, made of some non-magnetic metal, 
with a glass top or side to it, through which the pilot can 
read the bearing on the card. A mark is painted on the 
body of the compass, outside the bowl, in the direct fore- 
and-aft line, both of the machine and of the compass. It 
is called the "lubbers' line." As the compass card rotates, 
caused by turning the machine in the air, the figures on it 
register with the lubbers' line, and give the pilot the direc- 
tion in which the nose of the machine is pointing from 
time to time. 

The compass card is circular and is divided into 360 
degrees. The marking of the card is carried out clock- 




The dial of a compass. 



MAGNETIC VARIATION 91 

wise, i.e., N. = 360 degrees or o degrees; N.E. = 45 
degrees; E. = 90 degrees; S.E. = 135 degrees; S. = 
180 degrees; S.W. = 225 degrees; W. = 270 degrees; 
N.W. = 315 degrees; and N. = 360 degrees again. The 
lubbers' line, as well as the figures on the compass card, 
being painted with luminous paint, can be read in the dark. 
The cardinal points are N., S., E. and W. ; the quadrantal 
points are N.E., S.E., S.W., and N.W. It is worth remem- 
bering that each degree contains 60 minutes (denoted 60'), 
and that each minute contains 60 seconds (denoted 60") 
of an arc. One point of the compass is equal to 11° 15' o", 
which means 11 degree3 15 minutes, so that there are 32 
points in the compass. (See sketch on page 90.) 

Compass Error 

If the compass needle is not affected by local magnetic 
material in an aeroplane, its red end will point to magnetic 
north and its blue end to magnetic south. The angle that 
the needle is deflected from true north is equal to the mag- 
netic variation. The angle that the needle is further de- 
flected from magnetic north by magnetic material carried 
in the aeroplane is called deviation. The total error of 
the compass needle from true north caused by variation and 
deviation is called the compass error. Compasses must be 
swung from time to time to test their accuracy, as is 
explained in Chapter VIII, or if magnetic material is added 
to the aeroplane, in the shape of machine guns, bombs, tool- 
kits, etc., it will cause the needle to deviate from its correct 
angle. This error can be corrected, to some extent, as 
explained on page 129, by inserting small magnets in little 
holes provided for them in the fore-and-aft line, and also 
athwart the compass. On some compasses will be found a 
small wooden box fitted to the underside with holes for the 
accommodation of correcting magnets, while in others the 
slots for the magnets will be found on the top of the com- 
pass. 

A common trouble with compasses is caused by a bubble 
fopning in the liquid. To extract this the filler plug must 
be removed from the bowl, the bubble brought up into the 
plug hole, and distilled water added until the bowl is brim 



9i PRACTICAL FLYING 

ftdl. A fountain-pen filler or glass tube which will allow 
the bowl to be filled drop by drop may be used for the pur- 
pose. To counteract the expansion of the liquid due to 
changes in temperature, a small chamber of thin metal, ca- 
pable of expanding and contracting slightly, is connected 
to the compass bowl by a small passage through which the 
liquid has access to the expansion chamber. Sometimes a 
bubble can be removed by pressing the expansion chamber 
when filling the bowl through the plug. 

Great care is taken in compasses to insulate them from 
vibration. Sometimes the bowl is allowed to rest on a 
horsehair pad in a metal cup. It is also provided with rub- 
ber or felt shock absorbers, which assist in damping out 
the vibration and making the card easy to read. 

Compass Spinning in a Cloud 

The compass is an extremely reliable instrument, and 
pupils should accustom themselves to steering by it and 
learning to study its reading. If the compass card begins to 
spin when the machine is in a cloud, for instance, it is a sign 
that the machine itself is turning and not the compass card, 
the north point of which is always trying to point to the 
magnetic north as the machine is turning round. Sometimes 
the compass card can be used as a lateral level, for unless 
it is lying parallel to the horizon it shows that the machine 
itself is tilted. In the same way it can be used as a fore-and- 
aft level. 

In some compasses the card is designed to be read on its 
side instead of from above. For this purpose it is attached 
to the rim of a flat float inside which the magnetic needle 
is carried. The float is pivoted, and the marking of the 
compass card, being on its rim, can easily be read as it 
changes its position. This type of compass is read from the 
back, and the figures omit the final "o" in the bearings for 
the sake of clearness. Thus, when the compass card reads 
27 against the lubbers' line, which is also at the back of the 
instrument, the nose of the machine is pointing 270 degrees. 
The card, which is in the form of a vertical band round the 
rim of the float, is painted red and blue to represent the 
northerly and southerly semi-circles. This type of compass 



AIR SPEED INDICATOR 98 

is used a great deal on modem aircraft, and pupils would do 
well to familiarize themselves with its design and mechan- 
ism, as it is rather different from the more ordinary and 
older patterns, in which the compass card lies flat and is 
read from above. 



The Air Speed Indicator 

The air speed indicator is an instrument used to inform 
the pilot of his speed through the air and not over the 
ground. It consists, roughly, of two parts — ^the instrument 
and the Pitot tubes. The tubes are fitted to the leading edge 
of the top wing, generally to one side of the central fore- 
and-aft line of the machine, so as to be out of the way of 
the slip stream of the propeller, which would cause faulty 
readings. On a pusher or a double-engined machine, with 
the engines placed one on each side of the centre line, the 



.DirecHoTk of air. 



<i 



Pirejjvrc tube «o^o ended 
dectibnakl view 




iHaimitmiiMimtft^ii'tfiuiiHMMtHH 



— Nw dtitic tube , dojed crd ^iVK 




■■" Pr«5jure tube , dptn ended 
M. 3ectiQniil View . 



SucKof> Hibe ,3ecVior>ftl vicui. 



i 



rmrXTTTrSw St^tt tube. closed end wiW% 

Kolej at H^e 5ida . o\Aydf, 



itfta 



L 



Mr. 



Pmjure tube ,o)9eo . frk3idc 
5ccti6nal vieui . 



Aeroplane instruments. Pressure and static tubes used in con- 
junction with the speed indicator. The arrangement is known as 

the Pitot tube. 



PRACTICAL FLYING 

ccdlc . 



rcffurc side f^ box 
t«Kc side of box 
ubber difijaKragmidoHed lirtej 
Sowing itj mov«<Tierit wWicK 
; tranjmitted by juitaWe 
icchanijrrt to needte 



Aeroplane instruments. Section of air speed-indicator box, showing 
the rubber diaphragm and pressure and static sides of the in- 
strument. 

tubes could be fitted centrally, as the propeller draught 
would not affect them. There are two tubes arranged either 
side by side or concentrically, one inside the other. (Sec 
sketch on page 93.) One tube has its end open to the air 
and the other has its end closed, but is provided with a 
ring of small holes in its side, or, in the case of the con- 
centric tube, the inside tube has its end open to the air, 
whilst the outside one, with the holes in it, has its end ta- 
pered down and soldered to the inner tube. The first tube 
registers the pressure of air meeting it and rushing down the 
pipe leading to the inside of the instrument, which is en- 
closed in an air-tight case. In this case is a rubber dia- 
phragm, which is compressed by the force of air created by 
the passage of the open-ended tube through the air when the 
machine is in motion. This tube is called the pressure tube. 
The other tube is connected to the underside of the rubber 
diaphragm which divides the instrument box into two air- 



AIR LEAKS 95 

tight compartments, and transmits the pressure of the air 
at rest to this side of the diaphragm ; thus a balanced result, 
or reading, is obtained. The difference in the pressure in 
the two tubes is proportional to the square of the velocity. 
Air speed indicators under register with height, and to cor- 
rect this error a simple mefiiod is given. Multiply the 
reading of the air speed indicator by the reading of the alti- 
meter in the number of thousands of feet and divide by 60. 
This answer is the correction to be added to the reading of 
the air speed indicator. Example : 

100 X 6 

Air speed indicator registers 100 m.p.h. at 6000 ft. 

60 
= 10. Therefore the true air speed at this height is no 
m.p.h. 

Faults in Air Speed Indicator 

The up-and-down movement of the side of the diaphragm 
is conveyed by minute and very delicate mechanism to a 
needle, which works round as a pointer on a dial marked 
off in miles per hour or knots. Generally, the lowest read- 
ing g^ven is about 40 m.p.h. and the highest 160 m.p.h. To 
secure the correct functioning of the instrument, the fol- 
lowing points are of importance : — (i) The tubes should be 
pointing straight against the air stream when the machine is 
in the flying level position: if they are canted up or down 
they will, obviously, give a f?^ulty reading. (2) There must 
be no air leaks in the connections between the Pitot tube and 
the instrument. (3) Rubber joints are used in several 
places, and these should be properly secured by copper wire, 
not crossed or kinked, and should show no signs of perish- 
ing. These rubber joints are used so that the water which 
might accumulate in the metal tubes may be drained off 
when desired. (4) The instrument itself must be airtight, 
and for this reason a rubber packing washer between the 
glass cover and the body of the instrument must be properly 
fitted and the two parts screwed well home. Sometimes a 
careless mechanic may connect up the tubes vice versa to 
the instrument, or cross them at one of the rubber joints, 
so that an erratic reading will result. On most instru- 
ments the unions for the correct tubes are marked: P = 



96 



PRACTICAL FLYING 



pressure, or open-ended, tube, and S = static tube. It is 
never advisable to blow through the tube, as moisture from 
the mouth may get into it. The system can be tested bet- 
ter by sucking through the tube and theii closing the open 
end and seeing if the needle moves. If it does, there is a 
leak in the instrument or tubes. 



The Height Indicator 

The height indicator is operated by the pressure of the 
air, and is affected by variations of temperature. It con- 
sists of a dial marked off in hundreds and thousands of feet 
from zero to 10,000 ft. or 20,000 ft., depending on the 
scale and the type of work for which it is intended. The 
dial can be set to zero by turning a milled ring. This would 
be necessary after a fall or rise of the barometer, which 
would upset the reading of the indicator. It would also be 



regijterj 
Zero at 
ZQOjft 



det to 
Z«ro 



zLrv ^,.""*" 



i? 



Injtrufnaixt 
regij+erj 

400/'t 




Hoq/v 




Sfet to 



Two cases in which the height indicator might mislead the pupil 
The height indicator only registers the height of the machine above 
its starting point, so unless the ground over which the pupil flies 
is level with his starting point, the indicator will not be accurate. 



HEIGHT INDICATOR 




AeropUiK iattruments. Medianism of a hdght indicator 

necessary, in the case of the machine being transferred from 
one aerodrome to another, when the latter is either higher 
or lower than the former. The height indicator is always 
set to register zero at the ground-level where the machine 
is stationed, and it does not register sea-level unless a spe- 
cial compensation is allowed for between the height of the 
aerodrome and the mean height of the sea. The height in- 
dicator is simply an aneroid barometer. The indicator 
needle is connected by suitable and very delicate mechanism 
to an evacuated circular metal drum with corrugated top, 
which expands as the air pressure diminishes with height 
and actuates against a spring. It contracts again as the 
pressure increases, the spring transmitting the movement 
to the needle. As the metal of which the box is made is 
very thin, the pressure of the air tends to make it collapse 
altogether. This is prevented by fastening the bottom of 
the drum to the bottom or bed of the instrument, and the top 
side to a spring. As explained, the pressure of the atmos- 



98 PRACTICAL FLYING 

phcrc in the box compresses it against the spring, from 
which the movement of the box is transmitted by suitable 
mechanism to the indicator needle. The dial of the instru- 
ment is calibrated correctly in feet, so as to give approxi- 
mately correct readings of the amount of expansion or con- 
traction of the exhausted drum. With botii air speed in- 
dicator and height indicator there is a very considerable lag 
in their action, so that a reading of both instruments must 
only be taken as approximate at any given time. Height 
indicators give very little trouble in operation, but it is ad- 
visable, when anything goes wrong with them, to send them 
to an expert for repair rather than to tinker with their deli- 
cate internal mechanism. 

Contouring a Flight 

A barograph, or recording barometer, is sometimes used 
as a height indicator to show graphically the course taken by 
a machine in flight. The paper on which the recording 
needle writes is graduated vertically for this purpose in feet, 
instead of in millimetres or inches of mercury, and horizon- 
tally in hours and minutes. It is situated on a drum driven 
by clockwork and made to revolve very slowly. If a pilot 
winds up the clockwork in starting he will be able, at the 
end of his flight, to see his up and down course through the 
air, to work out how long it took him to climb to such and 
such a height, and to note whether his rate of climb and 
glide was constant. He can also tell at what height he was 
at any moment of his flight. These recording barographs 
are sometimes used by pupils undergoing height tests, or 
when making cross-country flights, and a great deal of use- 
ful information can be deduced from the study of the com- 
pleted chart of a flight. When a large number of these 
charts have been made, the instructor can use them to judge 
the skill of various pupils in climbing or gliding. A steady 
climb to 10,000 feet is indicated by a steady line, but if the 
line on the chart goes up in jerks or steps it shows that, 
for some reason or other, the pupil did not climb steadily, or 
else did not get the best results out of his engine whilst 
performing the test. 

Trouble with barographs may be caused by friction be- 



SIDESLIP INDICATOR 



99 



tween the pin and paper, or in the levers actuating the 
pointer. If the chart shows a number of quick, jumpy lines, 
friction in the mechanism is indicated. 



The Sideslip Indicator 

The best sideslip indicator is undoubtedly provided by a 
simple piece of string or tape fastened to a strut or cross 
bracing wire of the machine in view of the pilot. It is al- 
lowed to fly back by the forAvard motion of the machine in 
the air. When the machine is flying straight, or being 
turned with a correct amount of bank, the string will con- 
tinue to trail straight back dead in the fore-and-aft line of 
the machine. If, however, it tends to trail out sideways, 
either one way or the other, it indicates a sideslip in the 
direction away from which the string is trailing. Thus, if 
the string is trailing out to the left from its anchoring point 
on a left-hand turn, it shows that the machine is slipping 




r|.Fof^ 



Correct Turn . 
'(urrwng to H^« nghV . 




Shnyfispvq to ri^ht,frad>ine 
jli^n^ Id W^ Of oxAstAtdj - 



String jClyiKg to le)Ct,n>ath\r><i 
jlij>^«rg to right or mv«rd/ - 
kjr bank or inore nxldcr required 



Movements of the string sideslip indicator, which show whether 

turns are being made correctly. 



100 



PRACTICAL FLYING 



to the right or outwards. If, however, it is trailing to the 
left on a right-hand turn, it indicates an inward sideslip to 
the right. The pressure of the wind noticed by the pilot on 
his cheeks should also tell him that he is making a faulty 
turn. Wind on the right cheek on a right-hand turn indi- 
cates an inward sideslip to the right ; wind on the left cheek 
in similar circumstances would indicate an outward sideslip 
to the left. 



StDCdUP INDICATOR 
bubble 



3ubHc 




h> VTA righf ^ 



^%> 






*-*.; 



FOUC AND AFT LEVEL . 9ectiof>&l ^ide view 



Levct 0^ liquid io ^^Vn^ ^«^ VpS^Hon 

5* 



.7 
S 






DtgMf of De^nt. lo* a^^L^ 



«lr. 




1^ — m — ^Da5Kboa^<Ji 



Aeroplane instruments. The sideslip indicator and fore-and-aft 
level. A non-freezing liquid such as alcohol is used in both 

instruments. 

The cross spirit level is also used as a sideslip indicator. 
It consists of a bowed tube, filled with a mixture of alcohol 
and water to prevent it freezing. When the machine is 
flying horizontally level the bubble is in the centre of the 
level, which is marked o°. When a wing drops, the bubble 
moves away from the low side ; but on a turn correctly exe- 
cuted it will remain central, as the centrifugal force, which 
tends to throw the liquid outwards, will have been balanced 



CROSS LEVEL 101 

by the correct amount of bank. If the bank is too small for 
the turn, the bubble will travel to the inside of the turn as 
the centrifugal force will cause the liquid to fly outwards. 
The remedy in this case would be more bank or less rud- 
der. If the bank is too great, thr bubble will go to the out- 
side, while the liquid slips inwards. The cure is to put on 
more rudder or to decrease the bank. These remarks apply 
to all moderate turns, banked up to 45 degrees, and for all 
turns correctly executed, however steep, the bubble should 
remain central in the cross level. The use of this instrument 
in the air is much more likely to muddle beginners than to 
be of assistance to them. It is far better for them to learn 
to fly accurately by sight and feel or touch of the machine 
than to fly by the use of instruments, which, although use- 
ful as a means for checking the accuracy oi their judgment 
in flying, are liable to mislead them and to break down. 



Horizontal Sighting String 

Some pupils have been materially assisted in their early 
flying by fitting a string stretched horizontally level across 
the machine dead in their line of sight. This horizontal 
sighting string, when compared with the horizon, assists a 
pupil to maintain his machine laterally level. Unless the 
sighting string is parallel with the horizon, the pupil knows 
that he is not flying laterally level. If the string dips be- 
low the horizon to the left, he is obviously flying with his left 
wing down, and he must move the control lever to the right 
to pull the wing up, centring it again as the machine comes 
up level. Assuming that when tiie machine is flying level 
in the fore-and-aft line the string is set to be dead on the 
horizon, from the pupil's point of view, the pupil can see 
in a moment if he allows the machine to get its nose down 
or to climb. In the first case the string will drop below 
the horizon, whilst in the second it will appear to rise above 
it. It has been found a great help to the pupil to have the 
sighting string dead in line with his eye, as otherwise he 
would have to judge his position laterally and fore and aft 
by comparing the nose of his machine and the underside of 
the top plane with the horizon. This double comparison 




^laKrin^ Qtrin^ a\pov« Kori-^on ^Hour^ nrAchme ic chmkHng . 



^^9^^B^^^ 



I 



ti^ of Si^hV «r\drcAt^ b«^ doH«d lM\e$ 




The uses of the sighting string for determining if the madiine is 
fl)dng horizontally or laterally level, if the machine is climbing, 
flying level or descending. For preference, the string should be 
set to be dead in line with the pupil's eye and the horizon when the 
machine is flying level. 102 



FORE-AND-AFT LEVEL 108 

is too much for the beginner, who finds it difficult to gain 
any idea as to the position which the machine is assuming 
in the air, whereas with the string he -has only one point to 
keep in mind. The fitting of the string also teaches him to 
look out ahead of his machine, which is the proper direc- 
tion in which to concentrate, instead of looking at instru- 
ments or aimlessly watching odd pieces of ground, sky or 
machine that may attract his attention from time to time, 
which, until he becomes very much more proficient, cannot 
possibly assist him to keep the trim of his machine correct. 



The Fore-and-Aft Level 

The fore-and-aft spirit level consists of a triangular tube 
with a bulb in the apex of the triangle, which is set at the 
back of the instrument board. The front of the level is 
graded in degrees and lies flush in the dashboard, the liquid 
being arranged to register o° in the half-way position when 
the machine is flying level. When the machine is climbing, 
the liquid rises in the glass, and when the machine descends 
it recedes. This level is only useful in so far that it tells 
the pilot the degree of climbing angle of which his machine 
is capable under any particular set of conditions of engine 
power or load. Unlike the air speed indicator, which will 
always allow him to know if he is flying within safe limits 
(it does not matter whether his engine is on or off, or 
what the load is), the fore-and-aft level cannot be used for 
this purpose, as a machine might be able to climb at a cer- 
tain angle with the engine running all out or with a light 
load, but it could not reproduce this performance with a 
failing engine or full load. Thus the pupil should not de- 
pend upon the fore-and-aft level too much as a means for 
telling him his position in the air, i.e., if he is climbing, 
flying level, or descending. If he noticed that he was flying 
level under any particular set of conditions with the fore- 
and-aft level registering at a certain mark, he might attempt 
to keep the level at the same mark if he ran into a big cloud 
unexpectedly. Even then his air speed indicator would 
probably give him a better idea of his fore-and-aft position 
than the fore-and-aft level itself. 



104 PRACTICAL FLYING 

The Engine Revolution Counter 

The engine revolution counter can be driven off the crank- 
shaft, the camshaft, or the pump shaft of the engine. Pro- 
viding that a correct gear ratio is interposed between the 
shaft on the engine and the flexible shaft of the indicator, 
it will indicate the actual number of revolutions of the en- 
gine per minute. Like other instruments, the needle and 
figures on the dial are often treated with luminous paint so 
that they can be read in the dark. The dial is arranged ac- 
cording to the speed at which the engine runs. It may be 
graduated from 500 r.p.m. to 1500 r.p.m., or up to 2000 or 
more r.p.m. if the engine is a high-speed one. The chief 
troubles with revolution counters occur owing to the break- 
age of the flexible shaft, or the pin coupling at the engine, 
pump or countershaft connection breaking or coming adrift. 
Sometimes oil will work its way up the flexible shaft and 
cable and enter the instrument, where it will cause the hand 
to stick. The cure is to clean both the flexible shaft, the 
cable and the instrument with petrol. Revolution counters 
work either by centrifugal force or electrically. If the in- 
ternal mechanism breaks down, the instrument must be re- 
turned to an expert for repair. In the event of any of 
these instruments failing in the air, there is no immediate 
need for the pupil to land. 

The Watch 

A watch is always a useful instrument in an aeroplane. 
It should have illuminated fingers and figures and be well 
insulated from vibration. This is done by placing it in a 
felt-lined case. A watch being valuable not only to aviators, 
it is advisable for it to be secured to the machine, or else 
to remove it when not required, as in the case of a machine 
being left out in a field all night, for otherwise, when the 
pilot returns, he may discover that some one had appreciated 
the value of the instrument and appropriated it for his own 
use. 

A map carrier can consist either of a leather case with a 
celluloid cover through which the map can be read, or else 
of a flat tin or sheet aluminium box with a roller at each 



MAP CARRIER 105 

side. In the latter case, clips are arranged to grip the map 
in each roller. The map must be cut to the correct widtfi so 
that the carrier can accommodate it, and is then wound on to 
one roller and secured to the other. By turning the roller, 
the map is gradually unwound underneath the celluloid 
cover, which has to be removed to fit the map into the case, 
and stretch by stretch becomes visible to the pilot's eye. The 





FM sdloloid *vt« 




Half C»rr.er 


Roll Tyj>e 




Ma(f> Camer . 




=*.'-/, 





Two kinds of map carrier used for cross-country flying. 

principle on which this type of map carrier works is similar 
to the mechanism for winding up a Kodak film. It is chiefly 
useful when a long stretch of country has to be flown over 
where the course to be travelled is too great to be viewed 
easily on one map, and the one sheet may not cover the 
one journey. Several map sheets can then be gummed to- 
gether and cut so as to form one continuous stretch. The 
map case is carried slung round the neck by a piece of tape, 
but the pupil must be careful to see that it does not foul 
his controls, as it may do if it were left to dangle freely, 
or if it were hung up on the machine. 



106 PRACTICAL FLYING 

Petrol and Oil Gauges 

The petrol gauge consists of a vertical glass tube con- 
nected to the petrol tank by short lengths of pipe at the top 
and bottom. A tap can be fitted between the gauge and the 
tank, in which case the gauge will only register when the tap 
is turned on. The petrol takes up the same level in the 
gauge as in the tank, so that the pilot can see exactly how 
much petrol remains. He should remember, however, that, 
as the gauge will probably be fitted in the back of the tank, 
the reading will only be accurate when the machine is fly- 
ing level. When the machine is climbing steeply the petrol 
will mount up at the back of the tank and in the petrol 
gauge, giving a reading in excess of the amount carried. 
When the machine is descending the reverse occurs. 

Fitting Nuts and Bolts 

A point in connection with the arrangements of taps worth 
noting here is that they should always be designed to hang 
down in their running position. There will then be no 
chance of them closing themselves unexpectedly owing to 
vibration in the air. In the same way, the bolts should 
always be put in with their securing nut underneath, so that, 
in the event of the nut falling off, the bolt will still remain 
in position. In cases where bolts are put in horizontally, 
and not vertically, the head should always face the direction 
of flight where possible, so that, should the nut come off, the 
tendency of the bolt will be to remain in its socket. 

The sight feed oil pulsator domes, used on most rotary 
engines of the Gnome type, are connected to the oil pipe 
between the pump and the crankshaft. As the pump dis- 
charges a small amount of oil at each stroke of the engine, 
the force of the pulsation is also transferred to the oil in 
the oil pulsator dome. The oil rises slightly and then falls 
again. If the gear ratio between the pump and the engine 
is known, it is possible to calculate the number of engine 
revolutions by timing the number of pulsations per minute 
in the glass dome. In the Gnome engine the pump shaft 
turns at 7/4 of the speed of the engine, while in the Renault 
engine the pump shaft turns at 2ly of the speed of the 



OIL INDICATORS 



107 



A.r 



t>eWol 




oftuoa 3K0WJ cbrrcctr amour>t- oj- ^cWo) 



w\ taM%k 




ling. 






J 



Petrol and oil levels, showing why the petrol and oil gauge fitted 

to the back of a tank may mislead the pilot as to the amount of fuel 

remaining, unless he is flying level when he reads the gauge. 

crank-shaft. There is no pulsator gauge in the Renault or 
R.A.F. engines, which are commonly used in school ma- 
chines. An ordinary pressure gauge is often fitted instead. 
When the oil is cold and the engine just started up the 
pressure will be seen to rise, but after the engine has been 
running for seven or eight minutes it will drop gradually to 
its normal mark. 



Pressure Feed 

A similar gauge is used in connection with pressure-fed 
petrol tanks, into which air is pumped, either by a hand 
pump or else mechanically by the engine, or, again, by a 
fan operated by the passage of the machine through the air. 
Generally a pressure of 2 lb. or 3 lb. per square inch is suf- 
ficient, and should the pressure increase beyond normal, 
some kind of adjustably safety y^lve or tap should come 



108 , PRACTICAL FLYING 

into action to prevent the tank being unduly strained. Pu- 
pils are often liable to forget the necessity for keeping 
pressure in the petrol tank by hand pumping from time to 
time, and have suffered forced landings in consequence. 
The best type is that in which the hand pump is only used 
as a stand-by or for starting up, the pressure being me- 
chanically maintained as soon as the engine is nmning. 
Leakage of pressure may be due to the petrol filler cap 
not being properly screwed down, or to taps or safety 
valves not seating properly, in which case they must be 
ground in until an airtight joint is obtained. Failure to 
hold pressure may even be due to a careless mechanic fit- 
ting die oil tank filler cap, which generally has a hole in it, 
to the petrol tank and vice versa when last replenishing the 
machine. 

There are many other kinds of instnunents to be found 
on Service machines, but, beyond mentioning these, there 
is no need for the beginner to worry his head about them. 
Such instruments as a petrol flow indicator, radiator tem- 
perature indicator, bomb sights, aeroplane cameras, and 
aircraft course and distance indicator, are all used on ad- 
vanced Service machines ; but by the time that the pupil is 
able to fly a machine of this type he will find no difficulty in 
understanding or operating these fittings. 



One Instrument to Check Another 

From the knowledge of the possibilities of the instru- 
ments a pilot can very often use one as a check upon the 
other, or use two in conjunction in place of another which 
may have failed. For instance, in a cloud, if the compass 
card begins to spin, it is an indication that the machine is 
turning in the opposite direction, whereupon the pilot should 
know how to counteract it. By watching the compass card 
dip or rise, fore and aft or sideways, the pilot knows that 
his machine is doing just the opposite, and, accordingly, 
counteracts the movement with his controls. By observing 
the height indicator he knows if his engine is pulling prop- 
erly, for if he were to keep the machine at its normal flying 
speed and it were to drop, as shown on the height indicator, 



POSSIBILITIES OF INSTRUMENTS 109 




One instrument to check another. Showing how the air speed indi- 
cator can be used as a fore-and-aft level. If the machine flies level 
at 57 m.p.h., it must be descending at all speeds above that; and 
climbing at all speeds below until the stalling point is reached. 



this would be direct evidence that the engine was not giving 
its full power. The air speed indicator tells the pilot when 
he is climbing or descending, and also, when used in con- 
junction with the height indicator, it keeps him informed as 
to how the engine is running. The engine revolution count- 
er, in addition to indicating the revolutions of the engine, 
can be used to show whether the machine is climbing or de- 
scending as the revolutions slow down or increase accord- 
ingly, within certain narrow limits. 

The sideslip indicator may either be an instrument based 
on the principle of having an air speed indicator at each 
wing tip to register the difference in speed between the two 
wings, or it may take the simpler form of a piece of string 
allowed to trail backwards in the view of the pilot. In a 
cloud the cross level may be used to some extent to main- 
tain the lateral level, the pilot following the bubble with 
the stick. 



110 PRACTICAL FLYING 

Watching the Bubble 

The fore-and-aft level could be used if the air speed indi 
cator failed, as it might 4o through intense cold or condensa- 
tion and frost. Assuming that a pilot knows at what num- 
ber of degrees it is safe to climb the machine, a fore-and-aft 
level can be used successfully for flying, so long as the en- 
gine gives its normal power. The side-to-side level indicator 
shows, within limits, when one wing is up and the other 
down. The general rule is for the pilot to follow the move- 
ment* of the bubble with the control lever. If the bubble 
rises to the left side it indicates that the right wing is down, 
therefore the pilot moves the control lever to the left, i.e., 
he follows the bubble in order to counteract the drooping 
wing. This rule only applies to small deviations from the 
horizontal. The bubble is also used to indicate a sideslip 
on turns. On a perfectly-executed turn the bubble should 
remain central. If it moves towards the lower wing on a 
turn it shows that centrifugal force is flinging the liquid 
towards the outer wing — in other words, that the bank is too 
small and the machine is sideslipping outwards. If the bub- 
ble is near the top wing on a turn it indicates that the ma- 
chine is sideslipping inwards and that the bank is too steep. 



The Importance of the Watch 

The watch serves more than one purpose. With it a pupil 
can tell, more or less, his whereabouts, i.e., providing he has 
calculated his speed correctly. He can easily verify this by 
timing himself over the first division of the course which he 
has marked out on his map. He knows, too, when his petrol 
and oil supply may be expected to run out, how much day- 
light he has (an important factor if he starts on a cross- 
country flight on a winter's afternoon), and in an emergency 
he can often use his watch to tell him the north, in the case 
of his compass failing. This is done by pointing the hour 
hand to the sun, and by dividing the angle between it and 
12 o'clock, the result, in the northern hemisphere, being 
that the dividing line points to the south. If he lost him- 
self and his compass were to fail, he would come down to 



THE WATCH AS COMPASS 111 

find his whereabouts on the map with the aid of his watch, 
and then note some visible and prominent landmark on his 
right course. He would then fly to it by sight ; but, before 
reaching it, he should pick up two other objects on his cor- 
rect line of flight, which will help him to keep his course 
when be has left his first landmark behind. By repeating 
this process it is possible for him to arrive at his destination 
without the use of a compass. 

Testing the Speed Indicator 

The object of describing how one or two instruments can 
be combined to make a substitute for another is that, when 
one fails, the pilot need not feel lost. The air speed indi- 
cator may fail through a rubber joint breaking or a leak 
occurring, or even throu^ it being frozen up. This can be 
tested by blowing down the tube until the pointer shows 70 




112 PRACTICAL FLYING 

or 80 miles per hour : the tube is then sealed up by holding 
the tongue over it, and if there are no leaks the pointer will 
remain at the set mark, falling back to zero when the pres- 
sure is released. The engine revolution counter may suffer 
defect either through the oil being frozen or the drive 
breaking, while the height indicator sometimes fails or 
sticks. 



CHAPTER VII 
Map Reading 

IT is necessary for a pupil to be able to read a map before 
his aerodrome flights can be expanded to a cross-coun- 
try journey. Those who have studied maps for motor- 
ing or cycling before taking up aviation will find that map 
reading is quite a simple matter. It is necessary to become 
familiar with some of the more common terms used in map 
reading and map making. The following have been selected 
as being of value : — 

Bearing. — A true bearing is an angle which a plane or 
line makes with the true meridian or north. A mag- 
netic bearing is an angle a plane or line makes with a 
magnetic meridian or north. 

A Contour is an imaginary line running along the sur- 
face of the ground at the same height all the way round. 
Each contour represents a fixed rise or fall of so many 
feet from those next to it. This fixed rise is called the 
vertical interval, or, for short, "V.I." 

The Horizontal Equivalent, or, for short, "H.E.," is 
the distance in plan between two contours. 

A Gradient is a slope expressed as a fraction. Thus a 
gradient of i-ioth indicates a rise or fall of i ft. in lo, 
or I metre in lo metres, etc. 

A Datum Level is an assumed level, by reference to 
which heights are measured or compared. 

Hachures are short, disconnected strokes of the pen by 
which the shading of hilly features is effected. The 
strokes are drawn directly down the slopes. The closer 
together the hachures the steeper the slope. 

A Meridian is a true north and south plane or line, and a 
magnetic meridian is a magnetic north or south plane or 
line. 

113 



114 



PRACTICAL FLYING 



TrueNcHh 
Magmltjc 




How the true north of a map 
is indicated. 



Having mastered these 
terms, the first thing to do on 
looking at a map is to find the 
north. In cases where it is 
not marked, the top of the 
map may be taken as the true 
north, and the borders at the 
sides as east and west. In 
other cases, however, two 
lines will be found, one end- 
ing with an arrow indicating 
magnetic north and the other 
ending in a star indicating 
true north. Magnetic meridi- 
ans indicate magnetic north 
and can be used accordingly. 



Meridians on maps are generally true, and not magnetic. 



Reckoning the Scale 

The next most important point to look at is the scale of 
the map, for, without a scale, a map might depict a whole 
country hundreds of miles across, or merely a county or 
department. There are two methods of indicating the 
scale : firstly, by drawing one in inches, in which case it is 
stated on the map how many miles of ground are equal to 
I in. on the map; the second method is indicated by the 
words, "Representative fraction equals 1-100,000," or some 
other fraction. In the first case, assuming the scale is 2 
miles to an inch, it means that 2 miles on the ground are 
equal to i in. on the map. Thus, by measuring tiie distance 
in inches between any two points on the map, the pilot can 
at once find out how much this represents in miles on the 



fffrffffffj 



Scale ofOneLvh toOne StaJtuteMHe, 



— . R.F. — 

Fraction. 



2 



Snults 



A typical method' of indicating the scale of aviation maps. 



MAP SCALES • 115 

ground. Sometimes the letters "R.F." are used instead of 
the words "Representative fraction." The method of reck- 
oning the scale by means of the R.F. is quite simple. As- 
suming a scale of 1-100,000, this means that one unit on the 
map — it does not matter whether it is an inch, a millimetre, 
or any other unit — is equal to 100,000 inches, or millimetres, 
or any other unit which has been taken on the ground. The 
pilot can then work out the scale accordingly. If he works 
in inches in this particular case, he will find that i in. on 
the map is approximately equal to i mile 1017 yds., or, if he 
works in millimetres, that i mm. on the map is equal to i 
kilom. on the ground. Incidentally, this will show the ben- 
efit of using the metric system. 



Maps Without Scales 

It is possible, in certain circumstances, for a pilot to be 
faced with a map on which the scale is not marked. Ob- 
viously, before proceeding to use the map he must discover 
the scale. He can do this by finding two places he knows 
on the ground and recognizing them on the map. They may 
be two villages, a farmhouse and a clump of trees, or two 
towns. Now, he must find out by measuring — by mile- 
stone, or by hearsay, if necessary — the distance between 
these places on the ground. It can be assumed that it is 4 
miles: he then measures the distance between these two 
spots as shown on the map and finds that it is 2 in. The 
scale of the map in this case is therefore half-an-inch to a 
mile. 

How Contours are Indicated 

Having mastered the scale, the next thing to do is to 
study the methods employed on a map for illustrating graph- 
ically the features on the ground. He will find that heights 
are indicated on different maps in different ways. Some- 
times this is done by colouring, the darkest portions of the 
map being the highest, and the lightest the lowest. Gener- 
ally there is a column of colour at one side of the map, and 
the heights corresponding with the colours marked. The 



116 



PRACTICAL FLYING 



commoner method of indicating height is by contour lines. 
These can be seen on most maps in the form of irregular 
curved marks all over the map. A certain set height, called 
the "Vertical interval," is fixed as a height between these 
contours, and the amount of the vertical interval is some- 
times indicated at the foot of the map. It may be lo ft., 50 
ft., 100 ft., or 500 ft, according to the map. All ground 
at, say, 10 ft. above sea-levd is fiien joined up by a line on 



&lcvatior\ 




An elevation of contour lines indicated on the map, showing how a 
concave or convex form of hill can be recognized. 



the map, and, assuming the vertical interval is 10 ft., all 
ground of 20 ft., 30 ft., or 40 ft., and so on, is joined by 
means of lines, which result in the thin and wavy marks on 
such maps. Naturally, it is impossible for one contour line 
to cut another, for this would mean that one part of the 
ground overhung another considerably. If a pilot knows 
3ie height indicated by any one contour line, and also the 
vertical interval used, he can calculate, by counting the 
lines above or below and multiplying the result by the ver- 



CONTOURS 11 



^ 



tical interval (which is always given in feet), how much 
any other piece of ground is above or below the one he 
started with. 

He must remember that on some foreign maps the height 
is not marked in feet as in English maps, but, perhaps, in 
metres instead. When studying his map before making a 
cross-country flight, it is advisable for him to note the 
highest ground across which he has to fly, and also to cal- 
culate how high it is above his starting point. If, for in- 
stance, the aerodrome he started from is 600 ft. above sea- 
level, and there is ground 2600 ft. high ahead of him, he 
will know that when his altimeter, which he has set to zero 
at starting, shows 2200 in the neighbourhood of this range 
of hills, there is some chance of his hitting them. This 
might easily happen were he to fly into thick mist or fog 
during a long cross-country flight ; hence the importance of 
studying the heights or contour levels on a map before 
starting. 



Convex and Concave Configuration 

In certain circumstances it may be difficult to find out 
whether the contour lines indicate a dip or knoll ; but, as- 
suming that there is a river or sea coast on the map, the rise 
of the land can be calculated with this as a base; the flow 
of a river being known, the lines crossing towards the 
mouth must be lower than those nearer the source. Gener- 
ally, however, the heights of contours are marked. Some- 
times what is known as a spot level — a small triangle with 
a height appended to it — will be found at various points on 
the map. In passing, it may be noted that when the con- 
tour lines are close together the slope is steep, and when 
they are far apart the gradient is more gentle. The hill in 
which the lower contour lines are far apart and the higher 
ones close together is said to possess a concave slope ; where- 
as, in a case in which the top contour lines are wide apart 
and the lower ones close together, the slope is what is 
known as convex. In a concave slope, the whole of the 
ground from the top to the bottom is visible from either 
point ; but in a convex slope those stationed at the top and 



118 



PRACTICAL FLYING 



the bottom cannot see each other owing to the bulge in the 
side of the hill intervening. 

A further method of indicating height is by means of 
hachuring, which consists of a number of short lines drawn 
down the slopes of a hill. 



How Features are Indicated 

The colouring of a map is useful in other ways besides in- 
dicating height. Woods, for instance, are often coloured 
green, railways are indicated in black, roads in red or brown, 
and water in blue. Towns are often shaded in black, al- 
though, of course, this is only done in large-scale maps. It 
is necessary to familiarise oneself with these methods of 
indicating the main features and landmarks of the country, 
which will be of the utmost importance when making a first 
cross-country journey. 

There is still room for very great improvement in avia- 




How to read the conventional signs on a map. 



PICKING OUT LANDMARKS 119 

tion maps. Motor maps are of little use, as they generally 
show a confused mass of small details, which are quite un^ 
necessary to the aviator. All he wants are a few general 
landmarks depicted clearly and accurately, such as large 
woods, trunk railways, main roads, rivers, lakes and towns. 
In his work no one of these features alone gives him his 
bearings, but, rather, their relationship to each other. At a 
fair height, say, from 5000 ft. to 10,000 ft., many of the 
small details given in ordinary maps are unnoticeable. 




Maps of the Future 

Special aviation maps are being produced from time to 
time in which only main features that can be recognised by 
an aviator from a height are included. These maps, of 
course, are on a much smaller scale than the ordinary road 
map and present the advantage of including in one sheet 
quite large tracts of country, so that there is no need for 
the pilot to join several maps together in order to obtain a 
continuous plan of his course. When a pilot has flown a 
good deal over certain tracts of country, he will be able to 
pick out for himself any useful landmark which he can 
easily recognise. A peculiarly-shaped field, a row of houses, 
a bridge across a reservoir, a chateau or monastery with a 
curiously-shaped entrance drive, or a park placed in an iso- 
lated position, may give him clues as to his whereabouts 
which it would be impossible to mark on a map. There is 
certain to be very great improvement in aerial maps in the 
future, and it seems probable that photography may be 
called to the aid of the aerial map-maker. 



Studying the Ground Round the Aerodrome 

In a succeeding chapter on cross-country flight, such 
questions as studying the map, working out the course and 
finding the way when lost will be investigated ; but it should 
be distinctly understood that a pupil cannot put in too much 
time studying maps before he is actually to use them in 
flying across country. It is a good plan to obtain a map of 



120 PRACTICAL FLYING 

the country surrounding the aerodrome and to study the 
ground from the air, and then compare it with the map. 
This can easily and most profitably be done during the early 
solo trips in the vicinity of the aerodrome. Then, when 
the crucial test of map reading — a cross-country flight — ^is 
undertaken, the pupil will not find that flying by map and 
compass comes strange and difficult to him. 

Some countries are more naturally adapted to flying over 
than others, insomuch as they are more open and have 
fewer minor features to distract and muddle the aerial map 
reader. Certain parts of France have this advantage, and 
in view of the fact that many pupils may make their first 
solos over French soil, it is necessary to bear in mind that 
the scale of French maps is given in kilometres, and that 
the heights are recorded in metres. Eight kilometres are 
equal, roughly, to 5 miles ; i.e., a kilometre is, approximately, 
5^ of a mile. A metre is 39 ins., or rather more than a yard. 
A hill marked 1000 metres on a French map is therefore, ap- 
proximately, 3300 ft. high, and not 1000 ft. 

Explanation of Map Symbols 

The conventional signs used can be found at the foot of 
most maps. Churches are indicated by a black cross; if 
they have a tower, the cross is placed on a black square; 
if a steeple, on a black circle. A double railway line is 
shown by two thick black lines with intervals of wide spaces 
in the form of a ladder with very deep rungs. A single line 
is indicated by a thin black mark with small cross marks 
cutting it at frequent intervals. Woods are often shown in 
green with marks to indicate trees. Unfenced roads are 
shown by dotted lines, and fenced roads by two thin parallel 
lines. Railway tunnels can be found by noting where the 
railway line disappears and appears again an inch or so 
further on, according to the scale of the map. Sometimes 
the railway is dotted in where it goes underground. Bridges, 
whether over or under roads, rivers, or railways, are marked 
with a distinctive marking. Telegraph wires are sometimes 
shown by a series of dots and dashes. A railway embank- 
ment or cutting is shown by shaded lines arranged in a semi- 
circle about the cutting or embankment and at right angles 




■•SSWSffi 



sS^ 



A reproduction from the one-inch Ordnance Survey printed in 
colours, which should be compared with the chart of the Character- 
istic Features. 



THE PROTRACTOR 



128 



bo 120 ifo 10090 0070 eo so ^ 3or 




Angles are marked off from the point X, which is placed at the 
point of departure on the map, the instrument being laid N. and S. 

from o to o. 

to the line. In the case of a cutting, the outer sides of the 
lines are terminated by semi-circles. (See plate on page 

121.) 

The Protractor 

An instrument that is used considerably in flying, although 
it is not operated by the pilot in the air, is called the pro- 
tractor. There are many different models obtainable. Pu- 
pils can select one that suits them best. A protractor is 
a flat piece of wood or transparent celluloid marked off in 
degrees and in various scales and measurements for use 
with maps or charts. These measurements may either be in 
inches or millimetres, or both. A popular type of protractor 
is illustrated, the method of reading angles or bearings from 
it being shown. On the reverse side of the instrument will 
be found a method for reading off the smallest measurement 
in decimal points. A scale is drawn out in the manner 
shown. (See sketch.) One of the main divisions is sub- 
divided into ten, and lines are drawn at an angle across it 



J 2 3 ±S07_$»k> 




A B C D E 

Illustrating the use of the protractor in measuring the distance 
between two points to ten places of decimals. 



124 



PRACTICAL FLYING 



as well as' parallel with the whole scale, the horizontal lines 
also dividing the scale into ten. To measure any distance 
exactly, it is taken to the nearest main division of the ruler, 
say C (see sketch), and the extra piece which is less than 
one of the main divisions is measured off against the re- 
duced scale (E). If it measures over 6, but under 7, the 
exact amount can be calibrated by measuring along down the 
sloping lines. If the exact distance came to 6 on the top 
row of figures, plus 5 on the vertical row, the measurement 
would total ABC + -65 of E, so that, taking the length (A) 
as one unit, any distance can be measured in terms of that 
unit to two places of decimals. 

Another type of protractor consists of a square piece of 
transparent celluloid having a circle marked off in degrees 
from o to 360 described about its centre, attached to which 
is a piece of silk thread. At the top and bottom scales in 
metres and yards are marked off in convenient scales used 

in Continental maps, i.e., 
1/80,000 and 1/100,000. To 
take a true bearing with this 
type of protractor, the central 
point is placed on the spot 
from which the bearing is to 
be taken, with the N. and S. 
line of the protractor corre- 
sponding to the true N. and S. 
of the map. The silken thread 
leading from the centre is 
stretched across the protrac- 
tor and map to the point the 
bearing of which it is desired 
to take, and the angle it makes 
with the true N. and S. line is 
read off on the arc of the cir- 
cle. To lay off a course with 
this protractor, which is graduated in the same way as an 
aeroplane compass, the centre point is placed over the start- 
ing position and the silken thread stretched across the map 
and protractor, the arc of which it must cut at the desired 
angle. A pencil line made down the thread will give the 
desired direction. 




How to lay the protractor on a 
map. 



CHAPTER VIII 
Preparing for a Cross-country Flight 

THERE are certain pilots who, when told to fly some- 
where, hurry away into the air without proper pre- 
liminary study of their course and the country over 
which they are to fly. No wonder such aviators often lose 
themselves and meet with other mishaps. It may almost be 
said that careful preparation for a cross-country flight is 
half the flight finished. 

When a pupil is told that he is required to fly to some 
spot — which may be called "A" — from his aerodrome at 
**B/' he should first proceed to obtain a suitable map, with 
the main features clearly marked on it, if possible having 
the whole journey on one sheet, with a scale of 4 miles to 6 
miles to an inch. If his course lies across two adjacent 
sheets of a map, he must join them together with gum or 
glue and cut them to fit his roll map carrier. 

Studying the Map 

He should spread the map out in front of him on a table, 
examine it carefully, and decide upon the route he is going 
to take, which may not be in a direct line, owing to the in- 
tervention of large towns or defended areas. With a ruler 
he joins the points decided upon, and then, from the scale of 
the map, works out the distance of the flight. Probably, to 
begin with, it will not be more than 50 miles or 60 miles. 

Now, although it is possible to fly from place to place 
with the aid of a map alone, a pupil-pilot must remember 
that in his compass he has a more valuable friend than even 
his map. If he steers by compass alone and has calculated 
his course correctly, then, allowing for the time occupied 
and the speed of the machine over the ground, he can ar- 
rive at his destination without the use of the map. It is 

125 



186 PRACTICAL FLYING 

possible for a map to be blown away in the air, or for it to 
be difficult to read, owing to bumps, and the attention of the 
pilot being taken up by the manipulation of the machine. 
When it is remembered that a very great area of land can 
be seen from an aeroplane at a height of even a few thou- 
sand feet, the necessity of steering a course to a degree is 
not so important as on a ship ; moreover, bumps in the air 
make this almost impossible. 

Variation and Deviation 

Having been through a course of navigation, he should 
have little difficulty accordingly in working out a compass 
course by drawing a picture and, starting with true north. 



Hoit to bythe pratraetoron t/» 
map to rteiicffthe bearing t^ 
point Afiwn B . btariffg ^A la 
tfa'a case /i appi^amaUly S8'. 



true N. I 

adding or subtracting variation, which, if not marked on the 
map, must be obtained from a variation chart. This gives 
him magnetic north, and then, by applying deviation (which 
is due to the influence on the compass of local iron and 
steel of the machine), he obtains compass north, and can 
calculate what the compass will read when he is steering on 
the true bearing he has worked out from his map. 



) 



VARIATION AND DEVIATION 127 

For instance, let it be assumed that the pupil wishes to 
fly from B to A, two points on a map. He joins them 
by a line and then at B draws a true N. and S. line, 
which he can find, generally, by taking the side of the map 
as a guide as to the true N. and S., or else the true 
N. and S. may be marked on the compass rose on the map. 
He then measures the angles between the two lines, which 
will give him his true course. He does this by placing 
the centre of the protractor, on which angles are marked, 
on the point B in line with the true N. and S. line he has 
drawn, and reading off the angle that the line B — A 
makes with it. Imagine it is 58°. He should not have made 
any mistake either in placing his protractor correctly on 
point B, or in reading off the angle, because, at first glance, 
it is obvious that he wishes to fly rather more than N.E. 
of his present position at B, and he already knows that 
the compass is marked in a clockwise direction, from O, 
or 360°, at N., to 90° at E., to 180° at S., to 270° at W., 
and back to O, or 360°, at N. again. Therefore he knows 
that the bearing he desires must be 'a little more than 45°. 
He then makes a picture of his true course, so as to apply 
his variation and deviation correctly. Imagine the variation 
to be 15"* W. He draws a line on the picture 15° W. of 
north, and marks it north magnetic. He finds from the 
deviation table on his machine that at E the deviation is 
3° W., so he draws another line from B 3° W. of mag- 
netic north, as deviation is always calculated from magnetic 
north, just as magnetic north is calculated from true north. 
All he has to do now to find his compass course is to meas- 
ure the angle EBA. The picture has explained to him the 
following : — 

The angle CBA = his true course =: 58°. 

The angle DBA = his magnetic course 58° -^ 

The angle EBA = his compass course 73° -|- 3°= 

76°. 

By drawing a picture he can see whether he has to add 
or subtract his variation or deviation to or from his true 
course. 



128 



PRACTICAL FLYING 



The angle DBG = variation 

'^'*"^^ The angle EBD = deviation 

= 3'W. 

Of course, if the variation 
were 15° E. and the deviation 
3° E. instead, his picture 
would look like this. (See 
lower illustration.) 

The angle CBA = his true 
course = 58°. 

The angle DBA = his mag- 
netic course = 58° — 15° = 

A diagram of a compass course 43 • 

with the variation and devia- The angle EBA = his com- 
tion applied correctly. pass course = 43° — 3° = 

The deviation to be applied will be found in the devia- 
tion table, which should be pinned up in the machine 
he is to fly. Regulations are laid down that compasses 
must be swung or tested for accuracy after a ma- 
chine has been wrecked or reassembled^ after any new 
fittings have been added 77^^ /y^^^ 




P M^jnetHi North. 



ourse 



to it, when the position 

of the compass is changed, 

or when armament, such as 

bombs or a Lewis gun, have 

been fitted. If there is no 

deviation table, the pupil will 

be well advised to have his 

compass swung before he 

leaves. At the same time, so 

much country can be seen 

from an aeroplane that a small indicating whether variation or 

error m steering is not of vital deviation has to be added or 

hnportance. subtracted to the true course. 




Swinging a Compass 

The following is the best method of swinging a compass. 
At most aerodromes the pupil will find a cement slab with 



. COMPASS SWINGING 189 

eiglitlmes radiating from the centre, or lines plotted in 
the ground. These lines indicate the four magnetic car- 
dinal points of the compass, i.e., north, south, east and west, 
and the four magnetic quadrantal points, north-east, south- 
east, south-west and north-west. These Unes have been cor- 
rectly arranged by a compass expert with the aid of a land- 
ing compass, ana wi^^ be situated far enough away from 
metal sheds for the metal not to have any influence on the 
compass. 

The machine is then trestled up in the flying position, 
with its fore-and-aft line laid along the north and south 
lines on the ground. The pilot, or whoever is swinging the 
compass, can line up the machine by dropping a plumb line 
from the centre of the propeller and sighting along it to the 
tail skid, or another plumb line dropped from the centre of 
the fuselage until these lines coincide with the north and 
south line on the ground. It must also be made certain that 
the machine is dead level horizontally, i.e., from wing tip 
to wing tip. The lubber's line of the compass should be 
fitted in the fore-and-aft line of the machine. The compass 
reading is then taken, and it may be found that, owing to 
the influence of metal in the machine, it does not read mag- 
netic north as it should do. Deviation will always be east 
or west, and the pilot must then insert a small field magnet 
in a slot provided for the purpose, generally in a box 
under the compass athwartships. If the reading of the 
compass is less than the magnetic, the direction is easterly, 
or if the reading of the compass is more than the mag- 
netic, the deviation is westerly (or — ). Thus if the machine 
is placed to head E. by the line on the ground and the com- 
pass reads 95 degrees, the deviation is W. (or — ). If the 
deviation is westerly, i.e., the red end of the compass 
needle is swinging to the left, he must insert the red end 
of the field magnet to the left, so as to drive the red 
end of the compass back to north, working on the principle 
that, in magnetism, like repels like and unlike attracts un- 
like. He can vary the strength of the field magnet by in- 
serting it nearer or farther from the needle, suitable slots 
being provided for this; or he may use a smaller magnet 
until the error due to deviation is reduced to one degree or 
two degrees. He repeats this process with the machine 



PRACTICAL PLYING 



heading magnetic east and west, the only difference being 
that, when the machine is heading east and west, the field 
magnet inserted must be placed in the fore-and-aft line of 
the machine and not athwartships. 



Making a Deviation Table 

Having reduced the error on the cardinal points to a 
minimum, a deviation table is prepared ^ving the compass 
reading for the cardinal and quadrantal points, and also 
stating the amount of error in degrees east or west at each 
of these points. In calculating his compass course, the pilot 
must allow for this error, and if his course lies between 
any two of these points he can divide the error between 
them. For example, if the deviation is 2 degrees east on 
north and 2 degrees west on east, if his course is 45 degrees 
his deviation will be nil. A compass having been swung for 



A DEVIATION TABLE 



181 



3)^fi¥ level. 




'*"'*'''»*fcMSi»^ 



Plumb line. Pluenb' 



line. 



tLf. 



How to arrange the machine for compass swinging ; testing the fore- 
and-aft level of the machine. 

deviation, no metal should be added to the machine; in 
other words, the pilot should not place a lot of tools in 
his pocket, or place a bag of tools behind the compass. 

A table to be pinned up in the machine would look some- 
thing like this : — 



For Magnetic Course. 


Steer by Compass. 


Deviation. 


N. Oi 


legrees 


357 degrees 


3 degrees E 


N.E. 45 


» 


47 


tf 


2 " W 


E. 90 


» 


90 


ff 


Nil 


S.E. 135 


» 


137 


» 


2 degrees W 


S. 180 


» 


183 


» 


3 " W 


S.W. 225 


» 


223 


» 


2 " E 


W. 270 


» 


270 


» 


Nil 


N.W. 315 


» 


317 


99 


2 degrees W 



ISft 



PRACTICAL FLYING 



The Wind Factor 

The only other factor that has to be taken into account 
is the wind. From his navigation lectures a pupil can 
make an estimate of the speed of the wind and its variation 
in strength and direction at the height at which he intends 
to fly. He can incorporate this in the course he is working 
out, and, assuming that he knows the speed of his machine, 
he can also work out the approximate time the journey will 
take. Supposing that the pilot wishes to fly from B to A. 

True fiorth ^^ ., ^n • ^A 



20 30 



say 60' 




Direction cfmnd . 

JB . 50mp7iC 

Calculating the effect of wind on the course to be steered across 

country. 

He draws a picture and makes a scale of miles per hour, 
the line B — ^A being laid oil at the correct angle to the 
true north for his true course. Imagine a west wind blow- 
ing at 30 miles per hour. He draws a line from B in the 
direction that the wind is blowing, i.e., from W. to E., 
and marks off on that line a point C, distant the equivalent 
to 30 miles per hour on his scale. Next, with centre C 
and radius equal to the air speed of the machine, i.e., 60 
miles per hour, obtained from the scale, he describes an 
arc to cut the line B — A at a point, say, D, joins C — ^D, 
which will be the direction to steer, allowing for a west 
wind of 30 m.p.h. If he measures the angle that C — D 
makes, with the true meridian B — E, he will find that it 
gives him the correct course to steer allowing for the wind ; 
in this case it is 44° in place of the true course of 60° 
obtained without reference to the wind. By measuring off 
B — D from his scale he can obtain his speed over the 



VELOCITY OF WIND 188 

ground, allowing for the wind. In this case it is 82 m.p.h., 
as against 60 m.p.h. in calm air. In calculating the speed 
and direction of the wind, which is always given as "True," 
the pupil must remember that the velocity of the wind 
increases with height^ and that at 3000 ft. it may be twice 
as strong as on the ground, and may have veered as much 
as 20 degrees. 

The speed of the wind and its direction are best obtained 
froni the nearest meteorological office, but what is known 
as the Beaufort Scale is often used for determining the 
speed of the wind near the ground. It is given on the next 
page for reference. 

In a long flight of several hundred miles a pilot cannot 
have too many checks upon his journey. He must also re- 
member the time the machine can remain in the air, and 
for this reason it is wise for him to get into the habit 
of making these calculations even when proceeding on short 
cross-country journeys. 

Radius of Action 

This presupposes that he is already familiar with the 
quantity of oil and petrol carried by the machine and the 
hourly consumption of fuel. In out-and-home flights he 
should be able to work out his radius of action, not for- 
getting to allow for the wind and the time taken in attain- 
ing his height, otherwise he may run out of petrol on the 
return journey. 

For instance, the pilot may require to find the radius of 
action of his machine. If there is no wind the calculation 
is simple, assuming that the speed of his machine is 60 
m.p.h. and it can remain in the air for six hours. His 
radius of action will be : — 

60 X 6 

=180 miles. 

2 

If there is a wind, however, an allowance must be made 
for it. Assume that the wind is dead against him on the 
outward journey and with him on the return. Speed of 
wind 25 m.p.h., speed of machine 60 m.p.h., duration of 
machine six hours. 



1S4 



PRACTICAL FLYING 





THE BEAUFORT SCALE. 






A System of Calculating the Speed of the Wind. 




Force. 
0. 


Description. 

Calm 


Characteristics. 1 
Smoke rises vertically 


MJP.H. 



1. 


Light air 


Direction of wind shown 
by smoke drift, but not 
by vanes 


2 


2; 


Slight breeze 


Wind felt on face. Leaves 
rustle ; ordinary vanes 
moved by wind 


5 


3. 


Gentle breeze 


Leaves and small twigs in 
constant motion. Wind 
extends light flag 


10 


4. 


Moderate breeze 


Raises dust and loose 
paper. Moves small 
branches 


15 


6. 


Fresh breeze 


Small trees in leaf begin to 
sway. Wavelets form 
on inland waters 


21 


6. 


Strong breeze 


Large branches in motion, 
whistling heard in tele- 
graph wires 


27 


7. 


High wind 


Whole trees in motion; in- 
convenience in walking 
against wind 


35 


8. 


Gale 


Breaks twigs of trees and 
generally impedes pro- 
gress 


42 


9. 


Strong gale 


Slight structural damage 
occurs, chimney pots 
and slates removed 


50 


10. 


Whole gale 


Seldom experienced in- 
land; trees uprooted; 
considerable structural 
damage 


59 


11. 


Storm 


Very rarely experienced, 
accompanied by wide- 
spread damage 


68 


12. 


Hurricane 


Above 


75 



RADIUS OF ACTION 186 

On the outward journey his ground speed will be 60 — 
25 = 35 m.p.h. 

On the return journey his ground speed will be 60 + 
25 = 85 m.p.h. 

The ratio of the speed of his outward to his return jour- 
ney will be as 35 is to 85 or as 7 is to 17. Therefore the 
time he must take on his outward journey is 17-24 of six 
hours, and on his return journey 7-24 of six hours. There- 
fore the outward journey will take 4j4 hours and the return 
journey i^ hours. The speed of his machine on the out- 
ward journey is 35 m.p.h., which, multiplied by the time of 
4j4 hours, equals a radius of action of 148^^ miles. The 
speed of the machine on the return journey is 85 m.p.h., 
which, multiplied by the time i}i hours, equals a radius 
of action of 148^ miles. 

The wind will hardly ever blow directly along the de- 
sired course, so that to work out the radius of action for 
oblique winds a picture must be drawn as was done in the 
case of allowing for drift. The ground speed on the out- 
ward and return journeys can be calculated by the for- 
mula : — 

speed out X speed in 

Radius of action = petrol hours X 

speed out + speed in 
For instance, the pilot requires to find his radius of action 
to the S.W. on a 60 m.p.h. machine, air duration six hours, 
and with an east wind blowing at 24 m.p.h. As before, 
he draws a scale of m.p.h. (See sketch.) He takes the 
true bearing 225° from A and draws a line on it towards B. 
He produces this line in the opposite direction, i.e., N.E. 
He desires to fly as far in the direction of B as possible, 
at the same time leaving enough petrol to return to his 
starting point at A. Next, he marks off the direction of the 
wind from A, i.e., to the W., by means of a line on which 
he marks its strength by referring to his scale. This will 
be the point C. With centre C and radius (obtained from 
the scale) of 60 m.p.h., the speed of the machine, he cuts 
the line B — D both above and below A. These points are 
found at B^ and D^. Now the angle that CB^ makes with 
the true north line will be the course outward, which equals 
212°, and the angle that CD^ makes with the true north 



1S6 



PRACTICAL FLYING 



line will be the course homeward, which equals 58°. The 
distance AB^ equals the outward speed, e.g. (obtained 
from scale), 73 m.p.h., and the distance AD^ equals home- 



North True 



o 

%m 



iC 



to JO 40 30 00 



Direction cfwind. 

< 




Finding the radius of 

action by drawing a 

picture. 



ward speed, e.g. (obtained from scale), 44 m.p.h. Then, by 
applying the formula already given, he works out his radius 
of action as follows : — 

Radius of action 6 X 73 X 44 

= 6X73X44 

73 + 44 = 164.7 

117 

miles. This result allows of no margin of safety for a 
change of wind to a more adverse quarter or for time lost 
should the pilot lose his way, so that in his calculations a 
margin of at least 20 per cent, should be given. 

All these calculations will require to be verified in the 
air for safety sake, but the pilot will be surprised how 
accurately it is possible for him to work out his speed and 
course. 



LANDMARKS 187 



Finding One's Bearings 

Having worked out the course, it will be found useful to 
divide the line on the map which joins A and B into equal 
distances, each representing, say, lo miles on the ground; 
then, assuming that the pilot has calculated that his speed 
over the ground will be 60 m.p.h., if he takes his time of 
departure, even if he gets lost, he can tell approximately 
where he should be on his journey by looking at his watch. 
This will help him to find his bearings again, as a lot of 
ground is eliminated from his reckoning. Suppose, for in- 
stance, that a pupil lost himself for some reason after fly- 
ing for about 30 minutes. He will know, if he has divided 
up and numbered his line, that he must be somewhere about 
the third mark. All he has to do then is to find some land- 
mark in that neighbourhood and recognise it on the map, or 
vice versa. If the pupil realises that he has not sighted one 
or two principal landmarks that he should have done, he 
should come down and ascertain where he is. Of course 
it is of the utmost importance that all these preliminary 
calculations should be accurate, and if he calculates his 
course as north-east when it should be south-west, or reck- 
ons the wind is with him when it is against him, he is sure 
to make a mess of things ; hence the importance of checking 
preliminary calculations very carefully, as these mistakes 
are more common than one would imagine. 



The Inter-relationship of Landmarks 

He will now spend some time in studying his map, and, 
if possible, he should be able to memorize the principal land- 
marks, the order in which they will present themselves to 
him, and their relationship to one another. He should note 
the highest ground he has to fly over and should know the 
kind of landmark to look for. In cross-country flying he 
must remember that hills and valleys look flat at a height 
of a few thousand feet ; therefore, he should not waste time 
in trying to memorise them. It is such features as railways, 
large sheets of water, reservoirs, lakes, rivers, woods, towns 



188 PRACTICAL FLYING 

and sea coast that he should pick out. More important still 
is the inter-relationship between these features that he must 
visualise. He must study how railways and rivers enter and 
leave towns on or near his route ; how railways join each 
other or intersect; any curious curves or particularly 
straight stretches of railway line, river or canal ; the angles 
that towns, sheets of water or woods bear to each other; 
and, by doing this (which will come natural to him after a 
few cross-country flights), he will become familiar with the 
details of the journey ahead of him even before he takes 
the air. 

The Chief Characteristics 

It is a good plan, too, on a long flight to study the kind 
of country to be crossed. Thus the first portion may be 
suburbs, and then may come lo miles or 20 miles down the 
valley of a big river, where the ground is flat and marshy. 
The next stage may consist of thickly-wooded country, and 
the last stage, perhaps, of rolling downs and open farmland. 
If he lost himself on his journey, he could probably tell his 
whereabouts by the nature of the land under him. The 
importance of this preliminary study of the map by a pupil 
cannot be sufficiently impressed on him, and, to start with, 
perhaps, he will do well not to fly too high until he is pro- 
ficient in map reading and realises, for example, that a 
town which, at 1000 ft., he can recognise street by street 
and house by house, looks like a black smudge when he 
ascends to 8000 ft. or 10,000 ft. 



to 

of 



tie 
Jl« 

St, 

le- 






3* 



reparing and Studying the Map Before a Cross-country 

Flight 

An Explanation of the Accompanying Map 

Example. — Flight from aerodrome B, near Cardiff, to 
erodrome A, near Aberystwyth. 

Join A B, which will represent the line of flight. 

From the scale at the foot of the map find the length of 

e journey ^ 74 miles. 

Divide tiiie journey into equal sections of, say, 10 miles; 

ark and number these on the map. 

Work out the compass course by drawing line B C true 
lorth (obtained from true meridian) and measuring angle 
IIBA = 329 degrees. Apply variation, say 15 degrees west, 
n which case it is added = 329° -|- 15° = 344°. Also, 
ipply deviation from deviation card in machine, say 5 de- 
grees, east, in which case you subtract. Compass course 
then equals 339 degrees. A figure can be made out to cal- 
culate for wind as described elsewhere, but in this case it 
may be assumed that there is no wind. 

Assuming the air speed of the machine to be 60 m.p.h., 
the pilot calculates that the journey should take about ij4 
hours, and that each stage of 10 miles will be covered in 
10 minutes. Supposing he starts at 12 o'clock midday, he 
will pass the stage marked i, at 12.10; stage 2, at 12.20; 
stage 3, at 12 130 and so on. 

Cut the map with scissors or a knife the correct width to 
fit in strip form in a roll-type map-carrier, and mark the 
course and distance on it. [The section of the map printed 
IS so cut.] Then try and visualise the map and note the 
important landmarks, their relation to each other, and at 
what time and distance they should come into view. Note 
also the fact that most of the ground traveled over is moun- 
tamous, and therefore bad for landings. On stages i, 2, 3 
and 4 there are mountains 1500 to 2000 ft. high, but the 
worst ground, judging from the map, occurs between the 
stages 5 and 6. The very unfavourable character of the 

139 



140 PRACTICAL FLYING 

ground necessitates the pilot flying as high as possible, so 
that he will probably add lo minutes or so to the time of his 
first stage to allow him to gain a good altitude of, say, 5000 
or 6000 ft. 

Study the main features and landmarks of the map stag'e 
fcy stage. 

Stage I. — Caerphilly railways in X form make an excel- 
lent landmark; also the big wood S E; note the shape of 
this wood and also the water at Llanedeyrn and Whit- 
church. 

Stage 2. — Note the double railway lines, road and water 
leading direct on the course to Merthyr Tydfil, which should 
be easy to pick up, but which may be confused with Rhym- 
ney or Aberdare if the pilot is off his course at all. The lake 
to the W. of Aberdare would show him his mistake, how- 
ever, but here again it may be confused with the lake W. 
of Rhymney. 

Stage 3. — The road and two sheets of water on it are the 
best guides in this case. The pilot might note the strag- 
gling wood to his left and several sheets of water to his 
right, also the railway curving away to the N.E. from 
Merthyr Tydfil. 

Stage 4. — If the pilot has got so far he cannot miss cross- 
ing the Meath and Brecon railway, and he should try and 
make for the point where it joins the River Usk. The 
wood Yr Allt is an additional landmark at this point, and 
he should note its shape and relation to the river and rail- 
way. The large reservoir on his left is another good land- 
mark. 

Stage 5. — Note Llandovery, the river and woods on the 
left, and fly on until crossing the railway, taking note and 
not being misled by the tunnel. If in doubt then keep along 
on the compass course until crossing the banks of the River 
Towy, where there are woods on each side of it. Note 
Llanwrtyd Wells, the road, railway and river on right, also 
the wood N.W. of the town. 

Stage 6. — Nothing much to indicate the route except one 
small lake on the right and possibly woods round Lampeter, 
if the visibility is good. A difficult section for this reason 
and also because of the mountainous country traversed. 

Stage 7. — Tregaron forms an excellent landmark. Note 



A TIME TABLE 141 

the V fork of the roads, also the railway, which must be 
crossed at right angles. Then keep to the left of all woods 
and railways. Look out for the sea coast on your left and 
fly along it northwards until striking the first large town. If 
the pilot strikes the coast too high up he can easily find 
his mistake out as there is a railway running parallel with 
the coast to Aberdovey, whereas S. of Aberystwyth there 
is no railway. He should not mistake Aberdovey for 
Aberystwyth, because the mouth of the Dovey is a dis- 
tinctive feature in the former town and the railways are 
quite differently arranged. Having studied the map as in- 
dicated, he can fit it in his map case, roll it up and get ready 
to start. 

To assist the pilot, a rough time and distance table of the 
journey may be made as follows : — 

Distance. 
Time. Miles. Landmarks. 

12 o'clock — Start. Climbing for height, 

mid-day 

12. ID 7 Caerphilly Wood S X railways. 

12.30 20 Merthyr Tydfil, cross-roads and 

double railways and road direct 

on course. 
12.40 30 Two lakes on course. 

12.47 37 Cross railway, roads and river. 

12.54 44 Llandovery, river and woods on 

left. 
1.08 58 Round lake on right. 

1..10 60 Tregaron, railway and roads 

crossed at right angles. Sea 

coast should be in sight very 

soon. 
1.24 74 miles Arrive Aberystwyth, dense woods 

on right. 

To make certain that the table is correct the pilot could 
time himself over one of the stages and work out his speed 
from that. The woods, coloured green in the original, are 
diflScult to reproduce, and are, therefore, not easily discern- 
ible in the accompanying map, and allowance must be made 
for this. 



14S PRACTICAL FLYING 

How to Carry the Map 

The next thing to do is to fix the map in the most con- 
venient position. Some pilots prefer to have it pinned up 
in front of them on the instrument board, and others to have 
it slung round their necks in a roll-type map carrier. In 
either case the line of vision of the pilot should be removed 
as little as possible from straight ahead when he requires 
to read his map. This remark applies equally to instru- 
ments, which are better fitted in a group than when spread 
out over the dashboard. A third method is to carry the 
map loosely in the pocket ; but it may easily be lost, and, in 
any case, it is difficult to unfold or turn over when neces- 
sary. If the map is carried in a roll case slung round the 
neck, care should be taken that the case does not jam the 
control lever at any time. 

The pupil is now almost ready to set forth on his flight. 
Where it is possible, and the weather is changeable, it is 
a good thing to telephone to aerodromes en route, and 
also to his destination, and obtain a weather report, which 
will give such items as height of clouds, strength and direc- 
tion of wind, and visibility. He must glance at the baro- 
meter, too, and if the glass has fallen much he must look 
out for bad weather. Incidentally, the height indicator 
can be used as a barometer, and if set to zero one evening 
and found to read 400 ft. the next morning this indicates 
that the glass has fallen. 

Preliminary Details 

While waiting for the weather report, the pilot can look 
over his machine and engine as described previously. He 
must see that the petrol and oil tanks are full and that 
the instruments are working properly, that the height in- 
dicator is set to zero, the engine running well, and a bag 
of tools with a few spare parts, such as sparking plugs, 
valves, magneto contact breaker, some high-tension wire, a 
complete petrol pipe with unions, some insulating rubber 
tape and copper wire, are securely packed away in the 
locker. None of these things should be taken for granted, 
and it is no insult to the mechanics to look over the ma- 
chine one is going to fly. 



COMFORT ON LONG FLIGHTS 14S 

In some cases in England it is necessary to send warn- 
ing to the air authorities and to obtain leave from them 
before starting on a flight. It is advisable to find out 
whether the flight necessitates crossing any defended areas, 
which can be found out by telephoning to headquarters. 
These should generally be avoided, unless they have been 
advised of the flight before, otherwise the pilot may be mis- 
taken for an enemy aviator and dealt with accordingly. 

If the pilot is in the Service he must remember to take 
his Service cap with him. This can be stored in one of 
the drawers or lockers fltted to most machines. If a suit 
case is carried, care must be taken to have it firmly se- 
cured to the seat so that it cannot possibly foul the engine 
or machine controls. 

Position and Comfort 

It should be remembered that a cross-country flight of 
an hour or more is a much more tiring undertaking for a 



Kwi-i nearer ruddlcr-bar- 



"Tb«-a»^ to rodder- 
bar , allowing rvddsr 
K) be controlled 
w'iH\ one. jfooV 
•y t>«ce5rM-u . 



•tF/. 



comfortable position for the pilot is most important in long 
flights. Two points worth remembering are illustrated. 



144 PRACTICAL FLYING 

beginner than a few short trips around the aerodrome, 
although for his instructor the reverse is the case, as a 
straightforward flight is much easier than continual land- 
ings and turnings. The pupil should make himself as com- 
fortable as possible in his machine. He should avoid 
cramped positions at all times, and, if necessary, the seat 
can often be moved further back to give him more leg 
room. In view of the possibility of cramp in the legs, it 
is a good plan to fit toe straps on the rudder bar, so that 
the rudder can be controlled by one foot while the pilot 
stretches the other. A short man should make certain that 
he can reach the rudder when it is fully over with his knee 
just bent, and if he cannot he should fix a cushion, or 
cushions, behind his back so as to pad him up. Similarly, 
if his view is obstructed, he can improve it by adding an 
extra cushion or two to his seat. 

Clothing 

Plenty of clothing should be worn even in summer- 
time. Leather overalls are the best for general work, and 
sometimes it is possible for a pupil to draw a flying kit 
on loan. This can be supplemented in winter-time by 
woollen sweaters, mufflers and helmets. The hands and feet 
are the parts of the body most likely to be affected by cold. 
Big boots are essential, and with a combination of silk and 
woollen socks or stockings should help to keep the pilot 
warm. Goloshes or snow boots are also excellent, although 
somewhat clumsy. Many pilots object to the wearing of 
cumbersome gloves or boots on the ground that it inter- 
feres with the touch and feel of a sensitive machine; but 
in the event of their hands or feet becoming frost-bitten 
through insufficient protection, it may be remarked that they 
will have no feel at all. Fur gloves lined with wool are 
as warm as anything, and a fur flying cap, fitting close 
over the head, without ear holes, provides a suitable head- 
gear and one on which it is possible to raise and lower 
the goggles easily. Sometimes a pilot takes two pairs of 
goggles with him on a very long flight in case one pair 
should get lost, for it is a very bad thing to fly without 
goggles at any time. This is especially so on tractor ma- 
chines lubricated with castor oil, which is most injurious 



FINAL PRECAUTIONS 146 

to the eyes. The goggles should fit well and admit no 
draughts. Those fitted with Triplex glass are the best be- 
cause, in the event of a smash, there is less chance of the 
glass breaking and cutting the pilot's face or eyes. It 
is a good plan to carry a rag to clean off the oil and dirt 
that collects on the goggles and windscreen from time to 
time, or the pilot may use the loose end of his muffler for 
this purpose. Newspapers provide an excellent protection 
against cold, and may be worn under the waistcoat or in 
trousers or boots. It goes without saying that damp foot- 
gear should be avoided at all costs, more particularly by 
those who are prone to chilblains and bad circulation. 
They may receive some comfort by greasing their hands 
and feet before starting. 

One last word before the pupil takes the air. In view 
of possible forced landings, it is just as well to take plenty 
of money on the journey. This will not only make the 
period of waiting for relief more pleasant, but will also 
facilitate repairs if made on the spot with the aid of 
local motor men or carpenters, as well as the possible 
guarding of a machine by a farm labourer. 

The pupil should know the telephone number both of 
the place he has left and of the place to which he is 
going, in order to ring up either aerodrome when he re- 
quires assistance. A pilot's ticket and photograph issued 
by the Royal Aero Club forms a useful means of proving 
his identity. Some form of identification should always 
be carried. 

Fitness for Flying 

A pupil should never proceed on a cross-country flight 
if he does not feel physically fit, and he should have no 
hesitation in telling his instructor if he does not feel well. 
This also applies when the pupil is to make his first solo, 
as then he wants all his faculties and muscles working 
harmoniously, quickly and accurately together. There is 
no question of cowardice in a pupil saying that he does 
not feel fit or well enough to make a flight when in the 
early stages of tuition. The instructor will be able to 
judge from his previous experience of the pupil whether 
the man is really unwell or only pretending. 



CHAPTER IX 
Cross-country Flying 

THE pilot is now ready to take the air on a journey 
from B to A. Before starting, he notices the time 
of the day, or sets his watch to 12 o'clock, or to the 
nearest hour, so as to facilitate future reckonings. 

It is a good plan to climb to 1500 ft. or 2000 ft. before 
leaving the aerodrome, and then to set off the wind allow- 
ance, which can be compared with the course already found 
by calculation. This is done by taking some point on 
the line of flight already determined and one which is 
visible from the aerodrome. The pilot then flies on this 
line of sight and notes the reading of his compass, which 
will give him the course to be steered. This is a very 
simple and, at the same time, effective method of finding out 
the compass course without any mathematics or reckoning 
whatever. As an alternative, he can fly on his compass 
course, which includes his allowance for wind, and then 
note if it takes him along the line of country it should do 
on his map. If it does not, he must alter his course and 
note the bearing. 

The Height to Fly 



I 



Generally, when operating over friendly territory, any 
height between 2000 ft. and 5000 ft. is suitable, depending 
on the conditions of clouds, visibility and landing grounds 
and the highest portion of ground to be crossed. For in- 
stance, if a range of hills 1500 ft. high had to be crossed, 
and a start was made from sea-level, the pilot would not 
fly under 3000 ft. in their vicinity. An eye must be kept 
open continually for landing grounds, while the direction 
of the wind must be noted. Assuming that the machine 
has a gliding angle of i in 7, in still air a pilot can select 

146 



THE HEIGHT TO FLY 147 

any landing ground within 3000 yds., or, roughly, some- 
thing under 2 miles, from a height of 1285 ft. Therefore, 
the suitability of the ground that is to be flown over must, 
to some extent, regulate the height attained. In flying 
across the Channel or a very large city, a height of 10,000 
- ft. or more would be reached. 

■Having determined this question, the pilot then climbs 
slowly to the height at which he decides to fly. Avoiding 
clouds, either by flying under, over or round them, the 
pilot should, at any rate in his early flights, keep the ground 
in view the whole time, steering by compass and picking 



When the pilot has worked out his compass course, he can verify 
the accuracy of his calculation by flying by sight to a landmark that 
he knows is on his correct course, and checking the reading of the 
compass with his calculated course. In the illustration the pilot 
calculated his course to be 45 degrees, as shown in the small map 
inset. When he got into the air he found that his compass read 
40 degrees when flying by sight on the correct line of country, i. e., . 
to the first village. This indicates a gentle northerly wind, for 
which he bad not allowed. The line of flight made good is indi- 
cated by the thick, black line. 



PRACTICAL FLYING 



Flying in clouds. The pilot of the top machine is maintaining his 

lateral level by the cloud bank in front of him, although the ground 

horizon is obscured. The lower machine is descending through a 

hole in the clouds, through which the.ground is visible. 

up landmark after landmark as each presents itself to his 
vision. The higher he goes at first the more difficult will 
it be to recognise the ground under him by the map. 

Storms, Fog and Clouds 

There are many difficulties of various descriptions with 
which he may be faced. He may run into a rain, sleet, or 
hailstorm. These will generally be passed through, but hail 
may chip his propeller slightly. If a snowstorm is en- 
countered, the best thing to do is to turn back or land at 
once. Fogs or mists should be avoided and a landing 
made at once when there is some danger of a pilot becom- 
ing enveloped in one. Heavy banks of clouds can generally 
be avoided, and for pupils this is the best course, for even 
the cleverest pilots are liable to lose their bearings in such 



CLOUDS AND FOG 149 

circumstances. If a pilot should lose sight of the ground, 
and yet have clear air above, the machine can be maintained 
on an even keel by using as a horizontal level the very 
banks of clouds which hide the ground. Generally, these 
banks are more or less level, and, even if they are not, 
the pupil can take some well-defined cloud formation 
and maintain his position relative to it. If it is necessary 
for a pilot to fly through clouds or fog, he must watch his 
instruments most carefully and fly by them alone as best 
he can. He should brace his rudder square and try to 
keep his control lever central and vertical. If he is above 
the clouds and wishes to descend, he must first of all look 
round for any holes through which he can see the ground. 
In gliding down through these holes he must be careful to 
look out for other school machines which may be flying 
under the clouds. If there are no clear places in the 
carpet of clouds, he must select a spot where it seems to 
be thinnest and glide down through it quite steadily. 



A Natural Gliding Angle 

Most machines will take up their natural gliding angle 
with the engine switched off, and only the slightest pressure 
on the stick is necessary to maintain them in a steady de- 
scent. A pupil will find that being in a cloud is very much 
like being in a really thick mist on the ground. Everything 
is damp and dark. In fact, in some clouds it is so dark 
as almost to prevent him reading his instruments. His aim 
should be to keep on his steady gentle glide until he sees 
the earth again. He should keep a careful watch on his 
altimeter, and if he gets to within a few hundred feet of the 
ground and there is no sign of the cloud thinning, he can 
reckon that he has been caught in a mist or fog, and had 
better climb again, get up over it and look for its limits, 
which may be in a down-wind direction. He must fly 
down wind by compass and try and overtake the advancing 
fog. He must also keep an eye on his petrol supply, for if 
he were forced to land in a fog through lack of petrol his 
plight would be even worse than if he had to land with 
the use of the engine, which might save him from rimning 



160 PRACTICAL FLYING 

into houses or trees, seen at the last moment. Ground 
mists and fogs are undoubtedly the most dangerous and 
treacherous enemies of the aviator. There is no particular 
difficulty in climbing through banks of clouds. The pilot 
can twist and turn his machine upwards through the clouds, 
always making for the brightest spot, until, sooner or later, 
he will emerge into clear blue sky and perfectly calm air. 
Quite often, really bad bumps are experienced in and near 
clouds, and it is these that may upset the pupil's idea of 
balance in climbing or descending, so that he may emerge 
from them in some unusual position, which will not mat- 
ter in the slightest if he has sufficient height to right the 
machine again. Many pilots have noticed how their 
compass card appears to spin in a cloud, and they have at- 
tributed this peculiarity to electrical effects, although it 
seems more likely that it is their machine which is spin- 
ning, whilst their compass card is trying to point to the 
magnetic north during these evolutions. 



When Clouds Obscure Landmarks 

It is much more difficult to study the ground when it is 
cloudy than on a clear day, because the pilot can only see 
little bits of road, railways or woods, and it may happen 
that the very landmark for which he is searching to give 
him his whereabouts is obscured from him. For the same 
reason, it is very much more difficult to fly across country 
and find the way when visibility is poor than when it is 
good and permits high flying. The pupil might think that 
the lower he flies the easier it is to recognise the ground; 
but the opposite is the case, because he does not want to 
recognise the ground house by house, or mile by mile; he 
wants to be able to see long stretches of road, river or rail- 
way, and to see how they curve and intersect at distances of 
lo miles or 20 miles from his position. The further he can 
see ahead the easier he will find his map reading, and this 
means that he must have good visibility. After all, the 
map is a picture of the ground from a great height. He 
can see all his map at once, but he cannot, unless he be 
very high and the visibility be excellent, see all the ground 



AIR BUMPS 161 

that it depicts. If he could, there would be no need to 
use a map at all. He would get up high over his starting 
point and would fly by sight to his destination, even though 
it was 50 miles or 60 miles away. 



Atmospheric Conditions 

Another reason for flying fairly high is that the air will 
probably be much calmer there, and probably he will not 
be worried by heat or wind bumps. Early morning .or late 
evening are die best times for flying, for the atmosphere is 
both cooler and calmer then. Heat bumps generally begin to 
manifest themselves soon after sunrise, especially in sum- 
mer. To begin with, they may be within 100 ft. of the 
ground. They gradually ascend, until at mid-day they 
may extend to 2000 ft. or 3000 ft. high. Bumps are gen- 
erally found in the vicinity of clouds and inland sheets of 
wrater, although at sea the air is usually calm. In fact, a 
wrind from the sea is often a calm wind, in, the sense that 
it is not bumpy, although it may be blowing strongly. 
Pupils should get used to flying in bumps as soon as possi- 
ble, as the more they do it the less uncomfortable will 
they feel. In landing in a really strong and bumpy wind, 
it is a good plan to come down with a little extra speed, 
as they will have more control of their machines; but it 
must be remembered that, owing to the wind, the ground 
wrill appear to be coming towards the machine during the 
flattening-out process, very much more slowly than when 
landing in a calm wind, and the pupil must make allow- 
ance for this. Generally a pupil finds more difficulty in 
getting oflF in a strong wind than in gliding and landing. 
In landing in a strong wind in the vicinity of hangars, 
buildings or woods, the pilot must look out for sudden gusts 
and eddies set up by the wind striking these obstacles. 
These gusts may cause the machine to roll or drop 10 ft. 
or 15 ft Hence the need for giving as wide a berth as 
possible to buildings whilst gliding down to land. 

It is very unlikely that a pupil will be sent off on his 
first cross-country journey under unpromising weather con- 
ditions. In all probability he will have nothing much to do 



162 PRACTICAL FLYING 

except to steer his compass course, read his map and come 
down when he decides, landing in the aerodrome A just 
as he would at his own at B. 



Taking Bearings 

Suppose that a pilot loses his bearings. There are a 
number of ways in which he can find his whereabouts. He 
should know where he is approximately by calculating his 
speed and the time he has been flying, and then searching 
the country indicated on his map at the approximate point 
on his course which he should have reached. If his where- 
abouts are not to be found by this method, he must then 
circle round some clearly-defined spot on the ground and 
try to recognise it on the map somewhere near where he 
ought to be at that time, bearing in mind that, as explained 
in the chapter on map reading, it is the inter-relation of 
landmarks and main features that is the easiest to recog- 
nise. Another method is to come down low and read the 
name of a railway station, which can be done from a 
height of 500 ft. to 1000 ft., depending on the light and 
lettering on the nameboard. 

As a. final resource, he may land and inquire the way. 
It may happen, however, that, although he lands in friendly 
country, he is unable to find out where he is from the in- 
habitants; either he may not understand the language, or 
else there may be nobody there to help him. He must then 
study his map, proceeding as follows: — He must first set 
off from a side line on the map an angle representing the 
variation of the compass (in England this is generally 15 
degrees west). This line will be the magnetic north line. 
He must then twist the map round until the line that he 
has just drawn lies on the magnetic N. and S. line, as 
shown by the compass in the machine. This is called set- 
ting the map. He must compare the surrounding country 
with the map and try to recognise the landmarks. It may 
be the intersection of a road and river, or cross railway 
lines, or a town, church, range of hills or woods. He must 
recognise these places on the map, and, from their bearings 
to each other, work out his own position. Sometimes he 



TAKING BEARINGS 153 



* 






^ 1«1M 


•"••fl. 




• 




5* • 


* 
• 
• 

• 
• 


ij- rKowc\ irv 



The position of the Great Bear constellation in relation to the 

North Pole Star. 

can find this by walking to the nearest road and reading 
a milestone or signpost. 

If he is unable to use his compass to assist him, he 
must recognise two points on the ground and on the map, 
and then place himself between them. If he joins the line 
between these places on the map he will be somewhere on 
that line. By taking two more places in a similar manner, 
so that a line joining them on the map will be as nearly as 
possible at right angles to the first line he drew, he will 
discover his position at the intersection of the lines on the 
map. 

To find the true north, the watch method already de- 
scribed is useful, whilst at night the north star is the 
best guide. This can be found by locating the seven stars 
forming what is called the "Great Bear," the "Plough," or 
the "Saucepan." The two end stars at right angles to the 
others are called the pointers, and the north star will be 



164 PRACTICAL FLYING 

found in line with them, but at a distance roughly five times 
the space between the pointers. In England it is worth 
remembering that the aisle of most churches is built east 
and west, tifie altar being set at the east end. The sun 
also will help a pilot to find his position, as it rises in the 
east, is at the south at mid-day, and sets in the west, 
these pointers, of course, being only approximate. 



Landing on Strange Ground 

If it is necessary for a pilot to land off an aerodrome 
in order to find his way, or for any other cause, but not 
because his engine has failed, he will make more certain 
of hitting off his field by flying into it and using a little 
engine. As soon as he sees that he is going to land in the 
field safely he can throttle off. To make certain that the 
field is suitable, he should fly low once over it, scrutinising 
it for hidden pitfalls. 

Obviously, when landing on strange ground he should 
choose a field free from obstacles, for if he has to come 
in over trees or houses it will mean that there will be much 
less room for him to land. Here the best method of bring- 
ing down a rotary-engine machine may be described. The 
petrol tap should be shut, but the adjustable needle valve 
which regulates the mixture, and also the switch should be 
left alone. The sparking plugs will not soot up so readily 
when the switch is left on, and then, when the pilot desires 
to open out his engine again, he has only to turn on the 
petrol and his mixture is automatically correct, unless he 
has come down from a very great height, in which case a 
slight adjustment to the needle valve will compensate for 
the change in the density of the atmosphere. The rule 
is that the higher the machine is the more must the petrol 
be cut down, so that, on descending, he will have to give 
a little more petrol to correct the mixture. He should 
open out his engine at a height of about looo ft.; and 
can then switch on and off until he is certain that he is 
going to make the field. Then, especially on a fast ma- 
chine, he should leave the switch off altogether while com- 
pleting the glide and landing. 



"SLIPPING'' 166 

In bringing down a machine fitted with the Monosoupape 
engine, the switch is left on and the fine adjustment closed. 
The machine can be landed with the engine off 
and the fine adjustment is opened up to half nor- 
mal running position for taxying. The switch can be 
used if desired. In "blipping" an engine on the ground, 
a pupil should practise switching on as little as possible 
and allowing a long interval between the "blips." He 
should use as little petrol as possible, as it is obvious that, 
on a rotary engine (the only type where blipping is neces- 
sary), much less petrol is required to keep the engine run- 
ning at intervals compared with that required to keep it 
running continually. Hence the fine adjustment must be 
half closed when the engine is being controlled on the 
switch. Even in the air, the object should be to use as 
little petrol as possible consistent with even running, and 
if the machine misfires or chokes, even occasionally, the 
fine adjustment lever must be altered to obtain perfect re- 
sults. 

Propeller Torque 

Sometimes during the last few hundred feet the pupil 
may use his engine the better to gauge his distance. In 
switching on and off, or, as it is commonly called, *'blip- 
ping" an engine, either on the ground or in the air, the 
pilot will notice that the lateral balance of the machine is 
temporarily upset and that one wing will rise and fall as 
the engine is switched on and off. This is due to what is 
called the torque of the propeller. If the propeller revolves 
in a clockwise direction, judged from the pilot's seat, it 
creates an opposite turning movement of the machine, 
which will tend to revolve about its longitudinal axis in an 
anti-clockwise direction. Unless due allowance were made 
for this the machine would fly left wing down. But to 
compensate for the torque of the propeller more lift is 
given the left wing by increasing the incidence, or giving 
it what is called a "wash in." The greater lift allows the 
machine to fly laterally level, despite the propeller torque. 
When the engine is switched off for descending, the torque 
decreases, and so the left wing with the greater lift 



156 



PRACTICAL FLYING 



will tend to rise momentarily. When an engine is being 
"blipped" on the ground, the same sideways rock of the 
wings will be noticed. When the engine is on, the wing 
will drop, to rise again level as soon as the switch is off. 



Badly Trued-up Machines 

There is another point which the pupil must study 
whilst flying various types of machines. Sooner or later 
he will come across a machine which may not be perfectly 
trued up, either in the fore-and-aft line or else laterally. 
He may have heard of such-and-such a machine flying right 
wing heavy or right wing low. This means that the con- 




u/iU% Uv« *r\crea5«d incidence *'*5«J 



wWer\ 



cLp 



The torque of a clockwise- running engine or propeller (viewed 
from the pilot's seat) tends to make the machine turn in an anti- 
clockwise direction, i. e., to fly left wing down. This tendency is 
counteracted by a wash in or increase of incidence on the left wing, 
as shown by the blacked portion in the sketch. The dotted line 
shows what happens when the engine is switched off in the air, and 
causes the left wing to rise momentarily owing to the disappearance 

of the propeller torque. 



NOSE OR TAIL HEAVY 



16T 



trol lever has to be held over slightly to the left in order to 
make the machine fly horizontally or laterally level. If the 
control lever were placed central for flying, as it ought to 
be in the properly trued-up machine (which should almost 
fly and gHde itself, hands off), the machine would travel 
along right wing low. The cure for the trouble is either 
to increase the incidence or the ri^t wing or to adjust 
the aileron controls. The same trouble mi|^t equally apply 
to the left wing. 

Setting the Tail Plane 

A somewhat similar complaint results in the machine 
flying nose or tail heavy. If, in order to fly level in the 
fore-and-aft direction, the pupil has to hold the control 




corracf b>) rsdwcinq incidence, ort t^il , 
0'n<l>c^f«d b^ detVcd Una) 



Nej« hoNt) - 



Tbil hasMU. corracV' bu \ncT«»«itv incidonce oX'Vk'il, 
^ (.Mic»t«l b^j diiVVttd Ung ) . 




Examples of nose-heavy and tail-heavy machines, showing how to 
alter them by adjusting the incidence of the fixed tail plane. On 
some machines it is possible to vary the incidence of the tail plane 
in the air, and thus trim the fore-and-aft balance of the machine 
from the pilot's seat. 



108 



PRACTICAL FLYING 



Co«\Vro\ )«v«r, 




•-Ir^** 



.\«^i 



FlMino rtoKt u^iVvg dlowrx . cof^Vroi \«ver certr^l 



Corxtrol \«,v«f 




tAacKmft \evc\ - conVro\ \cvcr ovtr Vo ^Uo*j \eft^r^^ rv^\ wtoqo^ 



Examples of machines flying right wing low or right wing heavy. 

lever forward with a certain amount of pressure, the ma- 
chine is said to be tail heavy. The cure for this is to 
give more incidence to the fixed tail plane, which will cor- 
rect the fore-and-aft balance of the machine. A nose- 
heavy machine has to be held up by the control lever in 
order to fly level, and is remedied by the tail plane being 
rigged with less incidence. 



Restarting from a Field 

When restarting, the longest possible run should be taken, 
and if there are trees or houses at the far end it might 
be wiser to get off across wind rather than to chance get- 
ting off over the houses. It is quite easy to get off across 
wind, although it is a proceeding that pupils should not 
attempt until they are more or less confident in their flying 
capabilities. Supposing a machine is getting off side to 
wind, with the wind blowing from left to right, the pilot 



LANDING ACROSS WIND 189 

must keep the rudder over to the right, judging the amount 
accordii^ to the strength of the wind, and, fixing his eye 
on some point ahead of him, must steer his machine towards 
it, using right or neutral rudder and left bank, so as to 
attain this object. Once the machine is off the ground there 
is no particular difficuhy in the manoeuvre, and the pupil 
can turn into the wind as soon as he has gained a little 
height. It would be inadvisable to turn down wind until 
quite a considerable altitude, say, looo ft,, has been at- 
tained, owing to the difficulty of bringing off a forced land- 
ing if the engine failed. In landing across wind, the same 
procedure is followed, the wing nearer the direction of the 
wind being canted towards it slightly, which almost has 
the effect of making the machine land on one wheel. In 
practising this, the pupil will notice that what really hap- 
pens is tnat the drift, or crabwise motion, of the machine 
over the ground, due to the side wind, is compensated for 



The course of the machine over the ground is often crabwise, owing 

to the effect of a side wind. When the pilot wishes to land into 

the wind he must eliminate the drift or crabwise motion by turning 

into the wind, as shown by the dotted aeroplane. 



160 PRACTICAL FLYING 

by a slight inward sideslip, which allows the machine 
pursue a straight course over the ground. 

If there is ever any doubt about clearing an obsta,<=le 
getting out of a field, it is as well to remember that by t: 
ing off weight, such as by shedding the passenger, -to< 
cushions, or even running off some of the fuel, the mac:t» 
will take the air quicker and a great deal of the "run' ' c 



SIDC- SLIPPING 




In the position shown on the left the machine will sideslip. landing 

across the wind is rendered quite easy by landins with one wing 

down, and the sideslip into the wind which follows eliminates a 

crab wise course. 

be saved. AH this may have to be done to prevent a ma- 
chine having to be taken to bits and packed up as the only 
means of getting it out of a field. It happens sometimes 
that an instructor has to fly over to assist some pupil, and 
if the pupit is in a bad or difficult field the instructor should 
not attempt to land there, but must pick the nearest suit- 
able field. If he lands in a field where there is a doubt 
about getting out again, he can shed his passenger, get oul 



RESTARTING 



161 



4 the field solo, and pick his passenger up again by land- 
ng in a more suitable field near by. 

Before restarting in any strange field the pupil will do 
veil to make a journey on foot to survey the ground in 
tront of the machine. In extreme cases, crops or part 
)f a hedge may be cut down in order to allow a machine 



"TKa 4ccrc^3C ats Una tf cli'mb caused by t^^iWo^ off 
sKow^ 4Ue cour^ 4V>*.V H\^ m^cKinc WQvId "lake 
rea%or\ of dieaci a*r • 



;-' 






^-" 



.-.* 



..•-" 



..•" 




Direction ^ >H\r^ . 



«Ly I 



A point to be noted in taking off in the lea of obstacles. The region 
of the dead air which is shielded from the wind by the shed is 
shaded, and the course of the machine passing through it is indi- 
cated by the lower dotted line. The straight, upper line shows the 
angle of climb attained by the machine had it not passed through 

the region of dead air. 

to get off safely. If a pilot is faced with a small obstacle, 
such as a hedge at the end of a small field, the best way 
is to taxy up to it as fast as possible, and then to pull 
the control lever back suddenly, when the machine will 
jump the hedge, even though it has hardly yet gained a 
flying speed. Sometimes it happens that a machine has to 
be got off in such a way that it travels through air which 
is sheltered from the wind. The pilot must allow for 
this, as the lift obtained from air in the lea of sheds or 
woods, where the air is comparatively *'dead," is not nearly 



182 



PRACTICAL FLYING 



so great as the lift obtained if the machine could get 
straightaway into the wind. The same remarks apply to 
landing in a sheltered area where the machine will glide 
and run much further than might have been expected. 

In landing in a field, the pilot should always aim to 
land at the near-side fence just grazing the hedge, so 
that he has the whole length of the field for his run. 

In cross-country flying it happens sometimes that the 
engine fails and the pilot has to make a landing in strange 
country without its aid. This is called a "forced landing." 
One of the best tests of a pilot's skill is his ability to bring 
off a forced landing. Let it be assumed that the engine 
shows signs of giving out at a height of 3000 ft. A good 



► 




^tht<fSM.\ 






UrvO Worn V 



d)Mfld cry 



dtidc . 

- 50nr\.)f>*K. 
H«9 C^fTOMOd - Ht\ 



me. looutd \ar>d Wttr« 









Landing in a wind. Illustrating why it may be advisable to nose 
the machine down more at a faster gliding speed against a wind than 
in calm air, if it is desired to land in a certain ^eld. In this case 
the air speed of the gliding machine and speed of the wind are 
made the same, so as to illustrate the force of the argument. It is 
assumed in this case that at 60 m.p.h. the machine has a more efficient 
gliding angle than at 50 m.p.h. At 70 m.p.h. the machine would 

not glide so far. 



WIND DIRECTION SIGNS 168 

axiom to remember is that it is far better to land with 
some engine, even though it be but four cylinders work- 
ing out of eight, rather than to land without any engine 
at all. The power exerted even by four cylinders may 
be just sufficient to prolong the glide over a hedge which 
otherwise would have been short, or to help a pilot to 
jump his machine over the next hedge if he has overshot 
the mark. Hence, when an engine shows signs of gradu- 
ally losing its power, it is a wise plan to come down and 
investigate rather than trust to luck and wait for the 
engine to fail completely. On some engines it is by no 
means a rare occurrence for a partial seizure to take place. 
If allowed to go too far, this will cause the engine to stop 
dead, and it may be seriously damaged; but a landing 
can be made with half or three-quarter power at the pilot's 
control if the revolution counter be watched carefully and 
the sound and feel of the engine be studied. "Any motor 
is better than none," is worth remembering at all times. 
A gradual seizing-up of some engines, due to wear of the 
obturator ring, is indicated by the blueing-up of the four 
top radiating fins. This applies more particularly to the 
Gnome engine. 

Making Use of the Wind 

Most forced landings are due to total failure of the en- 
gine. As often as not this is caused by quite a small defect, 
such as a broken petrol pipe, faulty switch, or defective 
contact breaker on the magneto. Sometimes one or two 
plugs soot up, but they may right themselves in the course 
of a few minutes; hence the need for the pilot gaining 
some elementary knowledge of the vital parts of his ma- 
chine and being able to look over these points himself 
before starting. When an engine fails completely at a fair 
height, the pilot should switch oflf and turn off the petrol 
to prevent the possibility of fire, which is more liable to 
occur on a rotary engine than on a stationary one. The 
pilot then turns his machine into the wind. He does this 
automatically and accurately because he has always been 
noting the direction of the wind during a flight with a view 
to possible forced landings. He has been looking for smoke 
from rubbish heaps, haze over towns, steam from railway 



164 PRACTICAL FLYING 

engines, flags, shadows of clouds moving on the ground, 
and, when close to the ground, the movement of crops or 
the foliage of trees. If a strong wind is blowing across 
the machine, it is nearly always possible for a pilot to 
watch his drift as he glides down, always turning his 
machine away from the direction in which he is being 
blown. He must also calculate the strength of the wind, 
because, if there is a strong wind against him, his range 
of glide against it will be much shorter than if there were 
no wind. When a very strong wind is blowing he may have 
to select a field almost vertically under him, because the 
speeid of the wind is approximately equal to the speed of 
the machine, which, in such circumstances, would descend 
vertically on its glide to earth. For this reason a pilot 
should have some idea as to what his most efficient gliding 
angle is — ^that is, at what air speed the machine will glide 
the farthest. For the sake of example, let it be assumed 
that a machine has a range of flying speed from 40 m.p.h. 
to 60 m.p.h., depending upon the amount of engine used, 
and that 50 m.p.h. is its most efficient gliding angle. If 
the pilot brings the machine down either faster or slower 
than this speed he will undershoot his mark. Hence the 
importance of his knowing how to lengthen or decrease his 
gliding distance. 

Fast and Slow Gliding Angles 

To reduce the idea to extremes, the machine would come 
down vertically in a nose dive at, say, 120 m.p.h., and it 
would also come down vertically, or almost vertically, if 
it were allowed to descend stalling at, say, 30 m.p.h. The 
net result would be approximately the same. If a pilot 
were gliding down slowly at, say, 45 m.p.h., with the view 
of decreasing his run on landing, and he saw that he 
was going to undershoot his field, he could reach it safely 
by increasing the speed to 50 m.p.h. (i. e., his longest 
glide), although he would be. putting the nose down to do 
it. But if he were going to undershoot his field when 
already gliding at 50 m.p.h., his most efficient speed, he 
would undershoot it still more by putting the nose down 
and increasing the speed. He would also undershoot it if 



EFFICIENT GLIDING ANGLE 165 



1 TKc mojt evident ^lldir^g An^^^e 

3 A J lower Ana yiaH«r tut jKorVcr glide, 
H\e rt>acKir\« Almost ^tallirvg . 

glide , H\e nojc-dwe. ^ ^ ' A' 




Diagram showing that the distance travelled over the ground in 
gliding is smaller whether the machine is brought down faster and 
steeper or slower and flatter than the most efficient gliding speed 

and angle. 

he decreased his speed by raising the nose and gliding be- 
low his most efficient speed. Sometimes, when in doubt, 
it may be wiser and safer to come down on the fast side 
and then hold the machine off the grotuid as long as pos- 
sible, rather than to come down on the slow side with the 
possibility of stalling on the descent, especially when turn- 
ing. This applies particularly to getting off followed by 
an engine failure near the ground. To turn back and 
land in the aerodrome necessitates magnificent judgment 
and skill, as the pilot will otherwise certainly stall, sideslip 
and crash. Therefore, the rule is that, in 99 cases' out of 
100, it is better to go on and land in a straight glide even 
on bad ground. Hundreds of pilots, even of great skill 
and experience, have crashed through failing to observe 
this golden rule. In fact, the more experienced a pilot is 
the more is he likely to think that he is able to perform 
the extremely difficult manoeuvre of making an about-turn 
down wind from a low height. Sometimes it is a wise 



166 



PRACTICAL FLYING 



plan, when an engine gives out over bad country, to turn 
down wind for the first few thousand feet of the gliding 
descent with a view to reaching better country, the length 
of glide down wind being, of course, very much farther 
than in any other direction. The pupil should then turn 
into the wind at a height of about looo ft. or 1500 ft., in 
order to make certain of his field. However, he must not 
rely too completely on his altimetre, because the ground 
under him may be several hundred feet higher or lower 
than the spot where he last set his altimetre to zero. If 
he is very high up he can judge the direction of the wind 
by making a spiral and watching the way it blows him. 
By studying all these signs continually, he has no hesitation 
in which direction he ought to land. 







of gliae. 




Top: Illustrating the radius of glide of a machine in still air. 
Bottom: Showing how wind affects the radius of glide, which is 
greater down wind, but less up wind. In each case the machine is 
supposed to be at the apex of the cone of glide when the engine is 

throttled down. 



SELECTING A LANDING GROUND 167 



Selecting Suitable Landing Ground 

The moment that his engine stops he must put the nose 
of his machine down and begin to look for a suitable field, 
or, better still, a group of fields where he may land. A 
group of fields is chosen in preference to a single field be- 
cause he may easily overshoot or undershoot the mark, 
and it is therefore just as well to have alternative landing 
places. For preference, a grass field should be chosen 
possessing length in the direction of the wind, and without 
such obstacles as trees or houses surrounding it. A grass or 
stubble field, or a sandy beach makes the best landing 
grounds. Cultivated areas are generally comparatively 
level. Grass fields may have sheep or cattle on them and, 
naturally, look green from the air. Stubble is dark brown. 




Methods of judging the direction of the wind from the air. (i) 
By noting windmills. (2) By watching the drift of the machine in 
a spiral. If there is no wind, the machine would spiral round a 
fixed point on the ground. (3) Smoke from chimneys, trains and 
rubbish heaps. ((4) The drift of the machine near the ground. 

(5) The shadows of clouds. 



168 PRACTICAL FLYING 

a ploughed field looks black, and roots dark green. Golf 
courses can be distinguished by the yellow or brown patches 
formed by the bunkers. Plough, crops or roots are all 
bad, and only a pancake landing will prevent the average 
pilot from turning over. The golf course may be chosen 
if nothing better is at hand, and the same remark applies 
to parks and public recreation grounds. As roads and 
railways are generally bordered by telegraph wires, it is 
a bad plan to land near them, as the wires cannot be 
seen until the machine is upon them. 

Effect of Snow 

If the pilot is flying when there is snow on the ground 
it is practically impossible to pick out the kind of surface 
field desired. He can console himself with the fact that 
all the ground will probably be frozen hard, and the 
nature of the terrain is not of such importance as it would 
be under more ordinary conditions. He will find, however, 
that he will have to be more careful than usual in landing, 
as snow is very deceptive owing to the different lighting 
of the ground that it causes. Incidentally, he will find it 
much more difficult to recognise landmarks after a heavy 
fall of snow, as roads, railways, fields and villages are 
all included in one great camouflage. The same remark 
applies to extensive floods, which blot out distinctive bends 
in rivers that could be used to give the pilot his bearings. 

The lighting of the ground varies enormously if the 
pupil be flying late in the evening while the sun is setting ; 
he will fly in its rays, according to its height, after it has 
disappeared from the view of those on the ground. When 
he. comes to earth he will suddenly note the contrast in 
the lighting near the ground, where it is so much darker 
than it was when seen from high up, and for this reason 
he would do well to circle once around the aerodrome to 
accustom himself to the comparative dullness. 

Judging Distance 

Rules for judging distance are as follows: — A pilot is 
inclined to over-estimate distance in bad light, in mist, and 



MAKING "S" TURNS 169 

when the field and background are of the same dull colour. 
He will under-estimate distance when the light is very good, 
or when he is landing with the sun behind him. 

Another difficulty when landing is to tell from above 
whether the ground is level or not. This can only be seen 
when within 200 ft. or 300 ft. of it. Landing uphill means 
that the machine must be flattened out to the stalling point 
with its tail well down. A downhill landing, which should 
be avoided if possible, means a very much longer travel 
before the machine comes to rest. It is a wise plan always 
to land the long way of a field, or, in some cases, to make 
the diagonal from comer to corner, as the extra bit of 
ground gained may make all the difference between a 
crash and a safe landing. 

In the event of there being no field of ideal dimensions 
at hand, it may be necessary for a pilot to make a landing 
across wind. This is quite easily done, although it is not 
often practised in school flying. The method of doing 
this is described on page 159. 

Making an "S" Turn 

In any case, the procedure for hitting off the field, 
whether it lie into the wind or across the wind, is the 
same. The aim of the pilot should be just to glide over the 
hedge or ditch on the near side of the field. To do this 
he will find that a process called "S" turning is most use- 
ful. This consists of making a series of "Figure 8" or 
"S" turns as he descends. By this method the pilot can 
always keep his eye on the objective, if necessary making 
several "S" turns over the same ground. In making these 
turns, he must always turn towards the landing ground, and 
during the descent he should study the field most carefully, 
noting the position of trees and watching for any obstacle 
on the ground, such as agricultural implements and heaps 
of rubbish. If a spiral were attempted instead it would 
be quite possible for the pilot to find himself half a spiral 
turn out, that is, facing away from the field, at the mo- 
ment that he wanted to make his final glide into it from 
the last 200 ft. or 300 ft. "S" turns can be practised on 
any aerodrome, and they will be found very useful for 



170 PRACTICAL FLYING 

future emergencies. As the ground is approached they can 
be made shorter and shorter until there is no doubt that 
the field will be made safely. 

Another good method of bringing off a forced landing 
is to make a wide sweep into the field before turning into 
it. If the machine were falling short owing to the distance 
having been misjudged, due to the strength of the wind, 
the pilot can turn in quickly and much earlier than he 
would if he wanted to use up space. The latter would be 
the case if he were overshooting the mark. 

Another method used at times is to select a group of 
fields as before and to allow the machine to glide natu- 
rally towards it. When nearing the ground the pilot will 
have an excellent idea as to which field the machine is 
likely to hit, and, with a little control, he can help it to 
attain this end. The illustrations depict the various meth- 
ods described. 



Showing how a pilot, by making "S" turns, can always keep his eye 

on his objective, i. e., the field he intends to land in. (i) R^hl bank 
turning towards the field. (2) Nearly round. (3) Left bank turn- 
ing towards field. (4) The left-about turn nearly completed. 



TURNING NEAR THE GROUND. 



171 



WIND 
i 



l^iJae of f tcM . 



13 'facirva IK^ u/rooq 
fe land here 



1 




500 f^ 




5000 ff 



_ 



Wh/er. 



1 




1000 H 



Points to bear in mind when landing in fields. 

Turning Near the Ground 

In turning near the ground — an unwise procedure at any 
time — ^great care must be taken to maintain the speed of 
the machine by keeping the nose down. Hundreds of ac- 
cidents have occurred through pilots stalling their ma- 
chines by turning too flat when trying to make a forced 
landing and endeavouring to lengthen out their glide, 
or to avoid some hitherto unseen obstacle. At the same 
time, it is a good plan to land as slowly as possible in 
order to shorten the carry of the machine. A fast land- 
ing means a long run and the possibility of the machine 
hitting the hedge at the other end of the field. In order 
to avoid such an accident, the pilot should turn the ma- 
chine away to one side while it is running along the ground 
after landing, but this should not be attempted when the 
machine has a good deal of way on it. A pancake landing 
can sometimes be made intentionally on bad ground. To 
stop a machine on the ground the pilot must get the control 



17« PRACTICAL FLYING 

lever back to his chest, which brings the tail down and 
the tail skids into contact with the ground, where their 
added weight and friction soon slows up the machine. If 
this is done too soon, however, the machine may display 
a tendency to jump into the air again, and if it does this 
it may even pancake heavily. Pupils should remember 
to land slowly at all times, and especially is this neces- 
sary in hay, corn, plough, snow and marsh. Here, again, 
a pancake landing is the safest method. Frozen ground 
is generally safe, but it must be remembered that a ma- 
chine runs a very long way on it, and due allowance 
must be made for this. Incidentally, frozen ground is very 
much harder on a machine than thawed earth. The differ- 
ence can actually be felt after a frost, especially when 
giving landing practice. 

Steps to Take After a Forced Landing 

Assuming that the pilot has come down successfully — ^a 
creditable piece of flying, for even the best pilot may 
crash on a forced landing, because, even from a height 
of looo ft. or so, pne cannot make absolutely certain that 
the field chosen is suitable, and he cannot see wire fencing, 
small dips or hillocks, ditches overgrown with grass, ridges 
and ruts, heaps of stones, mole hills,, and even such things 
as small agricultural implements, any of which may be 
enough to overturn the machine — after landing, he should 
ascertain first of all what is the matter with his engine, 
and then telephone or wire to the nearest aerodrome or 
headquarters stating his whereabouts and describing the 
trouble. In stating where he is he should be able to say 
if there is a road near by suitable for the tender to use if 
one is being sent to salve the machine. When a pupil 
wishes to describe his exact position on a map, he can 
either give his bearings and distance from the nearest town, 
or from some obvious landmark, or he can report that he 
has landed on some letter in some place printed on the 
map, giving at the same time the map number and its name. 
Thus, if he said that he was down at the third "s" in "Sus- 
sex," or the "y" in "Canterbury," on Sheet 12 of Bacon's 
2-ins.-to-the-mile road map, his commanding officer, having 
a similar map in front of him, would know his whereabouts 



DIAGNOSING THE TROUBLE 178 

exactly, and would instruct the breakdown gang accord- 
ingly. If he has damaged his machine in landing, he must 
inform his headquarters of all the damage. If he mini- 
mises this, it is possible that the tender and the mechanics 
who may be sent out to his rescue with spare parts, owing 
to the insufficient information supplied, may not have 
brought all the necessary spares, and a second journey may 
have to be made ; hence the need for giving the very fullest 
details of the damaged parts and spares required. To do 
this, a pupil should know the correct technical terms for 
the various parts of an aeroplane and its engine. If the 
engine has failed it is always much more creditable if 
the pupil can diagnose the trouble and repair it himself. 
A broken petrol pipe, faulty switch or contact breaker, a 
sooted sparking plug, or even a broken valve can be re- 
placed with the aid of a few simple tools, and such opera- 
tions are worth attempting by a pupil possessing a certain 
amount of mechanical knowledge. If the machine is 
damaged, the pilot must take the necessary steps to secure 
it for the night. He must obtain assistance and move the 
machine, if this is possible, under the lea of a hedge, trees, 
haystack or house. The machine should be pegged down; 
that is, pegs are driven into the ground at each side of the 
tail and a little in front of each wing tip, taking care 
to insulate the rope from the wings and tail with sacking, 
straw or other material at hand. 

Pegging Down a Machine 

The machine is tied up to the pegs, which must be driven 
deeply into the ground in case a strong wind should spring 
up in the night and blow the machine away. Some slack 
must be left in the rope or there will not be sufficient play 
to allow the machine to rock slightly in the wind. Some 
machines are provided with rings under the outer struts 
for the purpose of being pegged down. It is then wise 
to cover the propeller^^ engine, pilot's seat and instruments 
with tarpaulins or sacking in order to keep out the damp. 
Sometimes it is as well to remove such instruments as the 
watch and also the tools from the machine. If the ma- 
chine is to be left out in a very strong wind, ruts may be 



PRACTICAL FLYING 




How to peg down a machine for ihe night. Pegs are driven into 
the ground at the wing tips and on eac5 side of the tail. Wings 
and tail are secured by rope, but not stretched too tightly to the 
pegs. The controls should be lashed central, and if there is a wind 
the machine is left in the lea of a hedge or house. The propeller 
and pilot's seat can be covered with sacking or oilskin. 

dug to accommodate the wheels, the tail can be jacked up, 
and the elevator control lashed back so as to present as 
little incidence to the wind as possible and thus to prevent 
the wind overturning the machine. Additional ropes can 
be slung round the propeller. 

Having secured the machine and made arrangements for 
a guard — in England local or military authorities or special 
constables will undertake the work, and in France the civil 
or military authorities, such as the mayor of the village 
or the commandant — the pilot can depart to his temporary 
headquarters to await orders or the breakdown gang. He 
should inform the guard and also his CO. as to where he 
can be found, or at what time he will be at such-and-such 
a rendezvous. If possible, he should give the number of 
the telephone or the name of the local post office or hotel. 



STARTING WITHOUT CHOCKS 



176 




Special precautions necessary to peg down a machine in the open in 

a strong wind. Note trenches dug for wheels and machine trestled 

up in the flying position, so as to reduce the lift on the wings. 

Starting Up Without Aid 

If he has been able to repair the damage himself, he will 
be faced with the problem of restarting his engine. He 
must obtain chocks — bricks, fence poles, or blocks of wood 
being used for this purpose. If he cannot obtain such 
things, he can get the observers — and there are certain to 
be plenty of these about— to hold back the machine while 
he tests the engine. He should explain to them where they 
can lay hold of the machine, i. e., by means of the struts 
and as near as possible to their lower sockets. 



Engine Starting Hints 

Some difficulty may be experienced in starting the engine. 
On a machine with a stationary engine which will throttle 



176 PRACTICAL FLYING 

down well, the pilot can start it himself. The explosive 
mixture is sucked in with the switch off, and possibly a 
rag over the air intakes to the carburetter. He then walks 
round to the switch, putting this to contact, closing the 
throttle so as to allow the engine to fire at a very low 
number of revolutions; he can then start the engine in 
the ordinary way by swinging the propeller. This opera- 
tion presents no difficulties whatever, for the pilot should 
have practised propeller swinging during his early flying 
experience. 

Swinging a Propeller 

Perhaps a word on swinging propellers may be of value 
at this point. Practise first with the engine off. The hands 
should be laid on the propeller about 4 ins. apart and 
about one-third of the distance from the tip of the pro- 
peller. The fingers should not hook over the trailing edge ; 
a ring is liable to catch on this if the engine backfires, and 
should therefore be removed. It is not advisable to stand 
on muddy ground, as a slip might cause an accident. 
When the switch is put on contact the propeller should be 
swung fearlessly, making sure that the engine is taken over 
compression. If this is done there is very little chance 
of the engine backfiring, which it is far more likely to 
do if the propeller is swung in a timid and half-hearted 
manner. Generally, the throttle should be partially open: 
the more the throttle is open the greater the compression 
of the engine to be overcome. It is a bad plan to stand at 
any time in line with the propeller, as, for instance, when 
holding chocks. Some pupils have difficulty in finding 
out which way the propeller revolves, but if they think 
out how it is designed with a view to cutting its way 
through the air, they should be able to distinguish the en- 
tering edge of the blade from the trailing. 

Starting a Rotary Engine 

On rotary-engined machines the method of starting up 
is not so simple. With local help, one of the onlookers 
may be taught to swing the propeller, or, alternatively, to 
switch the engine on and off as soon as it fires. There is, 
however, the chance that the inexperienced and probabl}' 



STARTING 



177 



highly-nervous farm hand, when in the pilot's seat, may 
lose his head, and, if there are no chocks, may run down 
the pilot, who is in the front of the engine after swinging 
the propeller. Therefore, a tip is given to provide against 
this mishap. Tie the switch to a peg in the ground Iwhind 
the machine, so that if the machine begins to move the 
switch will be pulled off by the peg. It may be mentioned 
here that the system on which a magneto switch works 
is to short-circuit the current, i.e., to make or complete 
the circuit. This is quite the opposite to a switch working 
in conjunction with accumulator ignition, where a switch is 
on when a circuit is broken and off when a circuit is 
made. 

Importance of Clean Wheels 

If the pilot finds that he has landed in a very heavy 
stubble field, or in thick mud, he should see that his 
wheels are clean before he restarts, as otherwise the mud 





'M 


jk ^^/ 


in 






ConVarf". 
Sod^ kept- uwll cte»r. 
Ke»d »rvd jKcHilderj 
b»ck . jCeet at>»^. 


&odv) And aTTi%j jiDuog 
riaKt round And c\«ar. 



The correct posit io 



178 



PRACTICAL FLYING 



and dirt will collect on them and will then be flung up on 
to the propeller by centrifugal force, whfch may possibly 
break or chip it. This is indicated by the whistling noise 
which a chipped propeller makes in the air. If a machine 
becomes bogged, assistance may be obtained and men sta- 



TrailiVig edge 



7 



^-— -3>*recVior\ o^ 




17 



Tra»\Ung edge 




Showing which way the propeller revolves, a point of difficulty with 

some pupils. 

tioned under the wings to lift the weight off the wheels 
whilst the pilot races the engine to move the machine 
forward. The pilot must be careful not to overrun the 
men supporting the wings. 

Causes of Forced Landings 

The common cause for a forced landing is running out 
of petrol, possibly due to starting with the tanks nearly 
empty, to a leak, or to a pilot forgetting to keep up the 
pressure in the tank on a machine with pressure-feed sup- 
ply. Some engines require doping or priming with petrol 
in the cylinders before starting. A dope-can, which is 
a small petrol squirt, should be carried on such machines 



RESTARTING IN COLD WEATHER 179 

when proceeding on cross-country flights; but if this is 
not at hand the engine can be primed by means of a 
rubber tube or a bicycle pump, or, in extremis, by soakinj  
a handkerchief in petrol flooded from the carburetter an(. 




How to taxy a machine out of heavy ground. The pilot races the 

engine while the men lift under the main spars of the wings. 

Planks can be placed under the wheels. 

squeezing out the contents. through the open exhaust valve 
or sparking plug orifice. A petrol funnel can even be 
made out of a piece of paper, and petrol poured through 
it into the combustion chamber. 

Wanning the Carburetter 
In cold weather, or when a machine has been out all ni^bt 
in the open, difficulty may be experienced in restartmg 
the engine. It should be noted that water-cooJed engines 
should have the water drained off from all points before 
being left out on a cold night, or the water may freeze, 
unless a non-freezing solution of glycerine is used. In 
restarting, hot water should be put into the radiator, care 



liiO PRACTICAL FLYING 

being taken to see that all taps are turned off first, 
hot rag placed round the carburetter and induction 
will help to vaporise the fuel. For easy starting 
engine may be primed and the sparking plug points plac 
close together, but not touching, although sooting up 
more likely to occur under these conditions. In some 
gines one particular plug may be liable to soot up. In 
case it may be given an extra wide spark gap, the id< 
being that the engine can be started up on any of the oth( 
plugs, the cylinder with the big spark gap plug chippii 
in when the revolutions of the engine increase and 
strength of the electric discharge at the plug jumps 
extra wide gap. 

Causes of Engine Failure 

Another frequent cause of trouble in starting is leal 
induction pipes. A useful method of preventing leaks 
such points is to wrap up the induction piping, especially, 
the joints and unions, with insulating rubber or medical 
tape, which will prevent the ingress of air and hence 
keep the mixture correct. 

A broken petrol pipe can be repaired with rubber tub- 
ing, a piece of which, the same size as the petrol supply 
pipe, should always be carried. Insulating rubber tape 
may be bound over the rubber joint and copper wire over 
the top, so as to make all secure. 

It has already been said that the engine may show signs 
of giving up long before it fails altogether. This may be 
due to faulty lubrication, or, on a Gnome, to a faulty or 
worn obturator ring, which can easily be discovered by the 
blueing-up of the top steel radiating fins of the cylinders. 
A faulty petrol feed will cause a drop in power, probably 
accompanied by spluttering noises. Generally this will be 
due to the perishing of the india-rubber or composition used 
in the petrol pipe, which, accordingly, should be inspected 
from time to time, and renewed if there are any signs 
of the composition perishing or crinkling up on the inside. 
A choked jet is a more rare occurrence, but it is wise to 
see that the filter and the gauze below the carburetter 
are cleaned occasionally. The same remark applies to the 
oil sump and strainer found on many engines. These 



PASSENGER SEAT PRECAUTIONS 181 

fiKShould be cleaned with paraffin occasionally. They must 
on he taken apart and replaced with fresh gauzes if the old 
[ins ones are cracked or broken, 

5 ji) A point worth noting when flying dual-control machines 
g i]:6olo is to see that there is nothing in the other seat to jam 
OTcthe control levers or rudder. Cushions should be strapped 



An example of good and bad airmanship. The pilot should land to 

the windward side of the town, so that in getting off again he has 

clear country in front of him. 

down. The belt should be fastened across the seat, and 
a suit case, if carj-ied, should be roped up in such a 
manner that it cannot foul the controls. 

Good and Bad Airmanship 

There are many other tips which the pupil-pilot will oiJy 
leam by experience, but the probability is that, . in the 
course of events, he will complete his journey successfully. 
An example of the kind of experience referred to may be 
given. The pilot has to land dose to one or other side of 



182 PRACTICAL FLYING 

a large town, the wind blowing from the east across the 
town. If he landed on the east side of the town, where 
the landing ground looked good, he would have to get off 
over the town, with a consequent chance of making a 
forced landmg in the town itself if his engine failed; so 
he lands to the west of tlie town instead, and thus has a 
clear line of country in front of him when he starts again. 

A Landing and a Lesson • 

Another case may be quoted where an experienced pilot 
would have saved his machine, whereas an inexperienced 
pilot wrecked his. In the course of a flight in the neigh- 
bourhood of an aerodrome, the switch on a Gnome engine 
machine failed, and the engine could not be switched off 
when the pilot desired to land. The pilot should have 
made certain of getting within gliding distance of the aero- 
drome and then turned off the petrol and glided home. 
Instead, he attempted to govern his engine on the petrol 
supply, with the result that h^ stopped it. He then saw 
that he would not reach the aerodrome, as the length of 
the glide of the machine, plus the amount that it would 
have been assisted by the engine being switched on and 
off in descending, was obviously shorter than the glide of 
the machine without the engine, so the pupil had to make 
a forced landing in some rough shingle, which he brought 
off successfully by pancaking. There was a strong wind 
blowing at the time, and in turning round, tail to wind, in 
order to get a long run to take off, he forgot the softness 
of the shingle and used too much engine, with the result 
that he attained too much speed, and, with his control 
lever too far forward, allowed the wheels to sink into the 
shingle, whereupon the wind got under his tail and slowly 
turned the machine over on its nose! It had to be dis- 
mantled and taken back to the aerodrome in a tender. 

A point to bear in mind when taxying down wind is 
that it is well to keep the elevator slightly down so that 
the wind keeps the tail low. 

Another instance was that of the pilot whose throttle 
control lever broke. As is the case generally, the carbu- 
retter control was set so that, in the event of the control 
breaking, a spring would hold it wide open; thus he still 



EXPERIENTIA DOCET 



183 



had his engine, although it was running all the time at 
maximum revolutions. Now the pilot knew that if he ran 
his engine for long at this speed it would almost cer- 
tainly break down, so he adopted the ingenious plan of 
climbing the machine at maximum power and steepness to 
a great height, and then switching off the engine altogether 
and making a long, slow glide down again. He repeated 
this process again and again, and eventually reached his 
destination safely. A less-experienced pilot would either 
have run his engine all out all the time, or attempted to 
govern it on the switch, both of which methods might 
have ended disastrously. In the case quoted, the engine, 
when climbing on full load, naturally slowed down con- 
siderably, and so avoided the critical number of revolu- 
tions. 

To restart the engine, should it stop when switched 
off, and there not being sufficient gliding speed to keep it 
going, it is only necessary to dive the machine steeply, 



Qr»\p^ ^i\o\' too Vow 







t"our\dl V\\e cHejt 



Two patterns of safety belts used to strap the pilot in his seat. 
The wide belt is far the better of the two. 



184 PRACTICAL FLYING 

when the force of air passing the propeller will generally 
restart the engine. 

These examples might be multiplied, but they serve to 
show the kind of thing that makes the difference between 
good and bad airmanship. 

The Homeward Journey 

In landing at "A" aerodrome, a pupil should remember 
to face the wind and land towards the head of the arrow 
if one is used. Sometimes a smoke flare is used to indi- 
cate the direction of the wind, in which case the pilot 
must land parallel to the smoke and towards the bucket 
from which the smoke is coming. Sometimes a kind of 
sausage balloon is fitted on the top of a pole for the 
same purpose. He should then taxy the machine up to the 
hangars and report himself to the duty officer and to the 
commanding officer, if necessary. Before returning, he 
should make certain that his petrol and oil tanks are suffi- 
ciently full, and take all the necessary precautions and 
preparations for the return journey that he did for the 
outward. 

H the pupil is returning late and is in danger of being 
overtaken by darkness, or if he loses himself late in the 
evening, he must remember to begin looking out for a 
suitable landing ground before it is too late. Darkness 
may come upon him, if he is flying high, quite suddenly, 
so that he must be on his guard against this and come 
down and land when the conditions of light are still favour- 
able. 

It is a bad thing to attempt a long cross-country flight 
on an empty stomach, and this is especially the case in 
early-morning flying, or when the air is very cold. A good 
meal or a hot drink should be taken even before a short 
ante-breakfast flight. 

Chocolate, tablet food or biscuits are good for taking 
during a flight, and will keep a pilot going for a long 
time; but it must be remembered that it is none too 
easy to dissect tablets from other articles and to withdraw 
them from the pocket. The best method would be to 
arrange them in a rack or ledged shelf in front of the 
pilot on the instrument board. 




Various methods employed to indicate the direction of the wind and 

other signs which can be observed b>[ the pilot, who, during all his 

cross-country flights, should pay particular attention and notice the 

direction of the wind. 



CHAPTER X 
More Advanced Flying 

WHEN a pilot has reached a certain degree of pro- 
ficiency, in all probability he will wish to prac- 
tise fancy flying, such as, on occasion, he has 
seen more expert aviators perform. Although this 
fancy flying, or stunt flying as it is called, is excellent 
training for aviators who are intended for scout or war 
flying, it should be undertaken with caution and at a fair 
height. "Stunting" near the ground is at all times danger- 
ous, and many good pilots have crashed through overlook- 
ing this warning. 

An Ascent of 10,000 Feet 

Any pilot who is to attain fair proficiency should be 
able to make an ascent of 10,000 ft. while still in the 
pupil stage. There is nothing difficult or dangerous in 
such a climb. It merely requires patience and a certain 
amount of nerve to carry it through for the first time. 
Pilots who are unaccustomed to long climbs are apt to 
climb their machines less and less steeply as they get 
higher, under the mistaken impression that they are stall- 
ing, or inclined to stall, their machines. It is true that, 
on the other hand, they may be able to get better results 
from their machines by climbing them slightly in excess 
of the lowest flying speed. This can only be tested by 
the watch. 

It may be mentioned here, perhaps, before going on to 
describe some of the fancy tricks that may be attempted 
at the higher altitudes, that when a pupil first goes up 
really high, i.e., in the region of 10,000 ft. or more, 
generally before landing again he should fly once round 
the aerodrome at loob ft., so as to accustom himself again 
to the appearance of the ground at this height. Owing 

186 



ALTITUDE AND MIXTURE 187 

to the difference in air pressure at various heights, the 
pilot will do well to descend slowly, and if he notices 
any strange feeling in his hearf or in breathing, to swallow 
now and then so as to equalise the pressure of the air 
inside his head with that outside. 

Less Petrol for High Flying 

As the atmosphere is rarer the higher he flies, he may 
find that he has to fly at a faster speed in order to get 
the best results. This is due to the pressure of air on 
the air speed indicator being less at heights for the same 
speed than lower down and nearer the ground. For the 
same reason he may notice that the carburation of the 
engine varies considerably, and he may find, too, that he 
will have to cut his petrol down in order to counteract 
the effect of the smaller percentage of oxygen in the air 
at considerable heights. This can be more easily done on 
a machine with a Gnome type engine, in which the petrol 
is controlled by a needle valve. If a hand control extra 
air valve is fitted, this can be opened to obtain a correct 
mixture. When descending from a height, the engine can 
be cut off altogether, to be started again at 1500 ft. or 
1000 ft. by simply diving the machine, which allows the 
pressure of air again to revolve the propeller. As pointed 
out previously, when descending with a Gnome engine ma- 
chine, it is wise to keep the switch on and turn off the 
petrol to prevent the sparking plugs becoming oiled up 
by superfluous oil flowing about the combustion chamber 
instead of being used up as it would be when running in 
the ordinary manner. On tractor machines it is quite 
difficult to stop the propeller in the air if any speed is 
attained; but in pushers the reverse is the case, and it is 
next to impossible to restart the propeller once it has 
ceased to revolve. 

A Vertical Bank 

The high climb to 10,000 ft. which has just been de- 
scribed will be the first advanced test that the pupil will 
attempt. He can next try a vertical bank — a term applied 
loosely to all banks of 45 degrees or over. There is no 



188 



PRACTICAL FLYING 




Uvct 

VccKcaI bai^k. 

♦«-- _ — , 

fo'^JS ^^^' ihak\%, 

H^w fio^w Trow* tWI 



Ufvtl 




m««»»««i 



J^ Course «* 



5tdC view of ITMd^M\tt. 



Vertical bank, a nose dive and zooming. 

particular difficulty in this manoeuvre: it is simply an 
exaggerated bank, and is performed by putting the con- 
trol lever and rudder farther over than in the case of an 
ordinary turn. As the aeroplane is now on its side, the 
nose of the machine must be trimmed to the horizo.n by 
the use of the rudder. Top rudder will make the nose 
rise in relation to the horizon, and bottom rudder will 
make it descend. To make the machine turn, the control 
lever is pulled back and slightly over in the opposite direc- 
tion to ease off the bank, because, otherwise, the bank 
would keep on increasing owing to the greater effect being 
exerted by the aileron on the outside wing which is moving 
so much faster than the inner wing. Thus the correct pro- 
cedure, in order to make a vertical bank, is to put the 
rudder and control lever over in the desired direction, 
then to trim the nose of the machine to the horizon, in 
the case of a level turn, with the rudder over (or below 
the horizon if it is a gliding turn), and, as this is done, 
to ease the control lever back to make the machine turn, 



MAKING A SPIRAL 



189 













.*• 



..*••• 



•» • • 



 • • 4 • 






.■:» Course of 

I 

'^- on spiCftL 



Sjjinnlij J^ 

Noje 

Dive 






^ 



<'"', 

• 

>, ' 



*^ 



4. 






■i,.^, 



The course followed by the machine in making a spiral descent, 
and what happens in a spinning nose dive. 

and slightly in the opposite direction to prevent the bank 
increasing. Now, to come out of the turn, it is neces- 
sary first to give the full opposite bank, and then, when 
the machine is nearly horizontal again, to give any oppo- 
site rudder that is necessary and to put the control lever 
central again and slightly forward. If the opposite rud- 
der were given before the machine were nearly horizontal, 
the effect would be to make the nose rise and a stall might 
result. If he continues his vertical bank round and com- 
pletes the circle, he is in a fair way to attempt a spiral, 
for a spiral is a circular vertical bank made with the en- 
gine cut off. 

Spiral Descents 

In making a spiral the pilot should always look down- 
wards and inwards towards the centre of the circle that he 
is making. If he finds his angle becoming too steep, he 
merely takes off a little bank, or pulls the control lever 



190 PRACTICAL FLYING 

back slightly if his descent is too rapid. He can judge 
of the accuracy of his spiral by watching his string or 
tape, the operation of which was described in the chapter 
on the instruments. If the spiral is correct, the tape should 
trail back in a perfect line with the fuselage of the ma- 
chine. When a bank or spiral becomes extremely steep, a 
curious phenomenon occurs: the rudder acts as an eleva- 
tor and the elevator as the rudder. This is a somewhat 
loose way of expressing what happens, for if one regards 
the rudder as a controlling surface operating the machine 
in a certain plane, it will always control the machine in 
this plane, regardless of its position relative to the earth. 
The elevator may be regarded in the same light and con- 
trols the machine in the same way. 

Inversion of Controls 

This inversion of controls is really due to the different 
positions assumed by the nose of the machine relative to 
the horizon. When one is flying level, a backward move- 
ment of the control lever makes the nose of the machine 
rise above the horizon; but if the machine is on its side, 
as it would be in a vertical turn, the same movement of 
the control lever makes the machine turn more quickly. 
In each case the nose of the machine is trying to reach 
the tail — ^an extreme instance of this being the loop. In 
the same way, left rudder will always make the nose of 
the machine try and meet the left wing tip, but if the 
machine is^on its side, say, in a left-hand turn, left rudder 
will make the nose of the machine drop below the horizon, 
although it is still trying to reach the left wing tip, which 
is, of course, underneath. 

"Zooming** 

The next trick he can practise is the "zoom," or the 
sudden jump of the machine several hundred feet into the 
air after flying near the ground. First of all he must re- 
member that he cannot effect a zoom until he has got up 
full I speed, for it is only the surplus speed that allows 
the machine to climb so steeply and suddenly. The manoeu- 



i 



NOSE DIVES 191 

vre is performed by pulling the control lever back sud- 
denly, which causes the machine to climb very quickly and 
steeply, and then putting it forward again when the ma- 
chine has practically reached the stalling speed, as indi- 
cated either by the air speed indicator (which is a bad 
sign owing to its amount of lag) or the general "sloppy" 
feeling of the controls. When a pilot notices this pecu- 
liarity at any time in the air he must beware, because 
it means that the machine has lost its flying speed and 
will stall the next moment unless he pushes the control 
lever forward and allows the machine to regain its ve- 
locity. 

Nose Diving 

The nose dive is the opposite to the zoom, and is per- 
formed by putting the control lever forward. It is wise to 
cut off the engine before making a nose dive, because this 
minimizes the strain on the whole machine. Nose dives 
should not be attempted too near the ground, and a pilot 
should not attempt too steep a dive to start with. He 
should see, too, that his belt is tight, as otherwise he may 
notice a tendency to slip through it on to his controls and 
instruments. He should also make certain that his goggles 
fit well, as if there are any air leaks in 4;hem they will 
cause his eyes to water and consequently blur his vision. 
He will do well to bring the machine out of the dive at 
over looo ft., in order to allow plenty of room for eventu- 
alities. To do this, he should pull the control lever back 
firmly but not too rapidly. He will feel the machine 
levelling up, and as the air speed indicator does not regis- 
ter as quickly as the machine changes position, he must 
not centre the stick until the instrument shows him that 
he is somewhere near his lowest flying speed. A nose dive 
can easily be followed by a zoom if the pilot pulls the 
control lever back rapidly. 

Looping 

Should he do this, and should he, in addition, put his 
engine on full at the same time as he pulls back his stick 
to the limit, he will, in all probability, loop, although 



192 PRACTICAL FLYING 



•I 




';f>en^inft 3w\tclicd oH. . 




Sdkk ncuh*^ . >c >j|^ 80*90 

fl\.O.w\. 

^Icd / .H^'Commcrc* 

••• / 

J^' Pull »H of 
,«** dive ocrMy . 



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•••*'^'Ef>qii>C 3Witd>Cd OO ^^ 



How to loop the loop. 

this is not by any n^eans the safest or best method of 
performing this very simple but, at the same time, very 
effective manoeuvre. A pupil who wants to loop should 
select a machine that is known to loop easily, such as an 
Avro or B.E.2C. He then ascends to a height of 3000 
ft. or 4000 ft., gradually puts the nose of the machine down 
to a speed of '80 m.p.h. or 85 m.p.h. (75 knots or 80 
knots), attaining this maximum by a more gentle descent 
than would be possible ^f he attempted to nose dive to this 
speed. He then pulls the control lever as far back as it 
will go, in one firm, strong pull, the effect of which is to 
cause the machine to rear vertically upwards and over. 
When he is upside down, he will see the ground below him 
and must then cut off his engine and a few moments later 
ease the stick, gradually centring it. The engine can be 
switched on again when the steepness of the nose dive has 
been materially decreased. The first part of the pull-back 
should be slower than the latter, on account of the greater 
speed of the machine in the early stages of the loop. The 



LOOPING 198 

control must be held back until the machine has completed 
the loop. 

Before looping, the pilot should see that the machine 
is perfectly trued up and that all the wires are correctly 
adjusted. He should also make sure that his belt is 
strong enough to hold him, in case he should make a 
bad loop or stall in a more or less upside-down position. 
If he did a correct loop there would be no need for him 
to wear a belt, as the cf^ntrifugal force of the manoeuvre 
would pin him to his seat. It is dangerous to have any- 
thing loose in the front seat of the machine, and such 
things as cushions should be removed before attempting 
any of these evolutions. In looping a machine like the 
B.E.2C. the pilot must brace himself to keep the rudder bar 
level, and also to pull the control lever back straight and 
not to one side, or else he may find that he will not come 
out of the loop square. In looping some machines in 



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Showing the right and wrong way of looping. It is a much bigger 
strain on the machine to pull it up for the loop after a steep dive 
than after a gentle one, where the necessary speed is attained 

gradually. 



194 PRACTICAL FLYING 

which a rotary engine is fitted it is necessary to use rudder 
to counteract the effect of engine torque when the engine 
is cut out, consequently it is advisable to practise on a sim- 
ple type of machine first. Looping is generally done into 
the wind. 

Tail Sliding and Spinning 

Another favourite trick of experienced aviators is to 
stall, or tail slide, the machine at a fair height and allow 
it to flutter down some distance. This is done usually 
by cutting out the engine and pulling the control lever 






1 To|> o^ sXskW, 

5) speed increajy^ J /;:>•'> ^ 

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mrtfHicQ /' 
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The ef]fect of stalling the machine, a perfectly safe and easy 
manceuvre given the necessary height. 

back. The machine then loses its flying speed and falls 
over on one wing or slides back tail first. If the nose is 
put down or the engine restarted, the machine will gather 
speed again and the pilot will regain control. If the 
engine is cut off and the pilot holds the control lever 
back all the time, he will come down in a series of stalls 
and their ensuing dives. 



A SPINNING NOSE DIVE 



195 



A tail spin, sometimes performed unintentionally by in- 
experienced pilots, is another stunt practised by skilled 
aviators. Sometimes it is achieved in conjunction with a 
nose dive, in which case the evolution goes by the name 
of the spinning nose dive or corkscrew spiral. What hap- 
pens in this case is that the pilot stalls his machine, pulls 
the control lever towards him and fully back. He does this 



before And 2J^€r RoU, 
oon\if>o tovMftrd^ observer 





r 




noil 

MafcKir« "Kimj over- 

on iKe ^anrve J>aH\ 
35 bej^ore . 



The various positions in a sideways loop or roll. 

with' the engine off, and then rudders hard in the direc- 
tion in which he desires to spin. He can get out of the 
spin, if he has sufficient height, by placing the controls — 
rudder and stick — central, whereupon the machine will 
take on a nose dive, when the engine can be restarted and 
the flight continued in the ordinary manner. Pupils who 
find themselves in a spin unintentionally must remember 
this. It is generally found that a pupil will get into a spin- 
ning nose dive through mating a faulty spiral on certain 
types of machine on which the area of the stabilising tail 
fin is too small. 

In stunting rotary-engined machines the gyroscopic effect 



196 



PRACTICAL FLYING 



of the engine, which causes the nose to go up if the machine 
is turned in the direction of engine rotation, and vice 
versa, will be noticed. 

The roll, which consists of making the machine loop 
sideways and continue in the same direction as it was trav- 
elling before the manceuvre, is done with the engine on 
or off. The pilot puts on speed and then pulls the control 
lever back as in a spin, and kicks on full rudder in the 
same direction in which he wishes to roll. To sideslip — 
which means that the machine descends sideways much 
more rapidly than it goes forward — full bank is given 
in the direction in which it is desired to slip whilst rudder 
is held off. 

Rolling and Staggering 

An evolution that is very easy to perform consists of 
making the machine take on a rolling and pitching move- 




The Immelman turn, in which the machine rears up, turns side- 
ways over the vertical, and comes out facing in the opposite direc- 
tion. Below are shown the movements of the control lever and 
rudder bar required in making this manoeuvre. 



VARIOUS "STUNTS" 



197 










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«\ yi, Ah .,^' /% 



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iby 



The falling leaf descent and engine cut-out, seen from the front 

and sideways. 

ment by working the control lever round and round in a 
circle and ruddering accordingly, i.e., giving a left rudder 
when the control lever comes round to the left, and right 
rudder when it comes round to the right. The effect on 
the machine is to make it stagger and see-saw like a drunk- 
en man. 



**Cartwheel," "Immehnan Turn," «Boot-lacing*' and 

"Falling-lear' Stunts 

Another variety of stunt is termed the cartwheel, which 
can be mistaken for a loop, in certain circumstances, by 
spectators on the ground. It is performed by getting up a 
little speed, by putting the control lever forward and then 
pulling it back, as in a zoom. When the machine is almost 
standing on its tail, but before it has lost flying speed and 
controllability, apply rudder and bank in the same direc- 



198 PRACTICAL FLYING 

tion. The machine will answer to the controls, cartwheel in 
the air, and come out facing in the opposite direction. A 
slight modification of this manoeuvre results in the famous 
Immelman turn. The engine can be cut out when the ma- 
chine turns about, and will allow it to dive, but if this 
stick is held fully back the machine will come out of the 
dive quite easily. This manoeuvre can be done with the en- 
gine off, the necessary momentum for the ascent and cart- 
wheel turn being supplied by diving. When the machine 
is pulled over, first on one side and then on the other, in 
the course of a long descent, the manoeuvre is sometimes 
called "Boot-lacing." Stalling turns are very similar to 
these manoeuvres, except that all way is lost at the top of the 
pull-back, and the machine then drops its nose suddenly 
and falls over on one wing tip, and so comes under con- 
trol again. The *Talling-leaf" descent is a modification of 
this manoeuvre. 

On some machines fitted with large rudders it is pos- 
sible to descend with the control lever right back. A very 
slow stalling descent, practically vertical and flat, results, al- 
though speed must be increased to normal in order to land. 
It is not easy to keep the machine from falling over on 
to one wing or the other during this manoeuvre, but it can 
be done by working the rudder more roughly than or- 
dinarily, so as to hold the wings up. 

A Flat Turn 

A very quick method of turning is attained by switdiing 
off the engine momentarily and kicking on full rudder, and 
then centring it. The machine will drop most of its fly- 
ing speed and turn round through about 90 degrees. In- 
deed, it would continue round and get into a spin if the 
control were not centred again. In a spin on some ma- 
chines, the lever must be pushed forward beyond the centre 
position. Upside-down spinning has also been performed, 
in which case the control is reversed, as it would be in 
upside-down flying, which has been done on certain types 
of Service machines. 

In all these evolutions it is a common occurrence for 
a pilot to get into the "wash" of his own machine, so that 



AERIAL FIGHTING 199 

he should not be alarmed if he experiences sudden gusts 
and bumps during these displays, for they are only caused 
by the air disturbances created by his own machine and the 
small amount of air space in which he is manoeuvring. 

Trick fliers at exhibitions have sometimes done such 
things as under loops and flying upside down ; but the ma- 
chines are generally specially constructed and strengthened 
for such work. Provided that they allow themselves enough 
height, there is practically no positional manoeuvre which 
it is not possible to perform on a machine, or from which 
the machine will not right itself — ^generally more or less 
automatically. 

Opinions are divided as to the advisability of allowing 
pupils to attempt the easier of these air tricks; but, pro- 
vided they are high enough in the air, such practice not 
only gives them added confidence in themselves and in 
their machines, but also undoubtedly makes them better 
pilots. A pupil should obtain his instructor's permis- 
sion before he attempts even the simplest of these man- 
oeuvres. 

Safety in Height 

For war purposes and aerial fighting, the man who can 
manoeuvre his machine the quickest obviously stands the 
best chance of downing his adversaries. On the other hand, 
no stunting near the ground or over bad country at low al- 
titudes should be attempted, for, sooner or later, the pilot 
will miscalculate his speed or distance, or else his engine 
may fail when he is at a critical angle, and he is unable 
to right himself before he crashes into the earth. More than 
one pilot has been severely injured or even killed through 
taking unnecessary risks such as these, or in his desire to 
prove himself a finer pilot than a rival. If any useful 
purpose were to be served by such displays, then by all 
means let them be attempted, even though the risk be great ; 
but when it is only a matter of personal rivalry, or dis- 
play before an admiring crowd, then such tricks are sheer 
foolhardiness. 



CHAPTER XI 

Night Flying 

THE question of night flying may now be discussed, 
the pupil having already been taken through the 
various stages of school flying until he may be con- 
sidered to be tolerably expert. Incidentally, it may be re- 
marked that even the finest pilots are constantly learning 
and adding fresh knowledge to their minds gathered from 
the hard school of practical experience. 

Night flying has often been regarded as a dangerous 
pursuit, probably owing to the number of accidents that 
occurred when it was first attempted on a large scale under 
unsuitable conditions. The lessons taught by these ac- 
cidents have brought about a greatly-improved state of af- 
fairs, and there is now no particular danger in practising 
night flying. This is a very different matter to undertaking 
a night flight under bad weather conditions against hostile 
aircraft. 

Aerodrome Lighting 

The first thing for a pupil to remember is not to attempt 

f to fly at night until he can land a machine by looking 

,. ' at the horizon, i.e., by looking ahead for a distance of at 

^ ,, , .''' least loo yards. At any time it is a mistake to watch the 

ground close under the machine, where it seems to be travel- 
ling very fast, and where an idea of the height that the 
machine is above the earth is difficult to estimate. In night 
flying this mistake must be absolutely avoided. As petrol 
flares are usually arranged on the night landing ground 
in the form of the letter "L," one can take the tail of the 
letter as the horizon in this case, and the long side as show- 

200 



'J 



NIGHT-FLYING MACHINES 201 

ing the extent of the landing ground and the direction in 
which to land. 

The next point concerns the machine. Practically all 
night flying done in England is done on stable machines, i.e.^ 
a machine that will practically fly, land and bank itself 
automatically. Obviously, the strain of flying at night is 
much reduced by the use of such machines, which are also 
capable of automatically righting themselves if they should 
get into a dangerous position. 

It is a good plan for the prospective night pilot to prac- 
tise flying and landing at dusk. He can then carry on with 
his flying later and later, until, when he gets a fine moon- 
light night, he will notice little or no difference between his 
flying conditions then and at dusk ; indeed, many pilots think 
that dusk flying is more difficult owing to the rapidly-chang- 
ing light. It is also obvious that he must know by heart 
his own aerodrome and any traps here may be in getting 
oflF or landing. He can familiarise himself with other aero- 
dromes in the neighbourhood. 

Daylight Practising 'i^v /^ 

It goes almost without saying that a night pilot must be- 
come familiar with the handling of his machine by day be- 
fore attempting to fly at night. This remark applies almost 
to any piece of mechanism, for the more the man and ma- 
chine are one or in sympathy, the better will be the results 
obtained from them. Therefore, the night flyer should prac- 
tise all day what he intends to do at night on the identical 
machine he will use. The machine should be rigged in such 
a manner that it will climb slightly if the control lever is 
let go. The object of this is that the machine will fly at a 
more or less uniform and medium speed. It should be ad- 
justed to fly level with the throttle half shut. In practis- 
ing for night flying by day it is a good plan for the pilot 
to watch his instruments more carefully than he would for 
daylight flying. He can practise watching his sideslip and 
air speed indicator and correct the machine by these. He 
should also watch his altimeter creep up or down accord- 
ing to the variation in the height of the machine, and note 
how it lags when the machine descends rapidly. 



202 PRACTICAL FLYING 



Getting OfF at Night 

In getting off at night it is very important for him to 
remain stationary for at least one minute at the end of the 
L lights, facing the short bottom end of the L, which will 
indicate the length of his run and impress on his mind the 
lie of the landing ground which he will have to use when he 
returns. He should count the number of lights and cal- 
culate the distance allowed him. He can also take note of 
any particular obstacles near at hand which he will have to 
avoid either in landing or getting off. In getting off he 
must be very careful not to swing. If possible, he should fix 
his eye on some distant light to steer for, and he should 
never attempt to turn under a height of 500 ft. or 1000 ft. 
He should not take the machine off the ground, but, in- 
stead, he should allow it to fly itself off. This is very im- 
portant indeed. He can practise this by daylight and will 
find it quite a simple operation. The proper time to leave 
the ground is the moment when it is difficult to hold the ma- 
chine down any longer. 



Keeping the Flares in View 

In the air he should make certain that he keeps the flares 
if he wishes to keep them in view continuously, not fly over 
them, but rather to one side. Up to a height of 6000 ft. he 
should pay particular attention to this, but must remem- 
ber to keep right away from the flares if he wishes to 
keep them in view continuously. At the same time, he must 
keep within gliding distance of the aerodrome, so that, if his 
engine fails or if unfavourable weather conditions be- 
gin to appear, he can be certain of his landing ground. If 
there is any suspicion of a ground mist he should come 
down at once. If more then one machine is practising at 
the same time, he should arrange beforehand some kind of 
signal or lighting whereby each pilot can recognise the 
other's machine. Alternatively, each pilot can arrange to 
fly in a certain direction so as not to interfere with the 
other. Very*s light may be fired from time to time if there 



LANDING AT NIGHT 808 

is nothing better at hand. All night pilot pupils should 
avoid clouds so far as is possible, for they will obscure the 
aerodrome flares and the pilot may lose himself, or find him- 
self in an uncomfortable position through losing his hori- 
zon. If the clouds are high up this does not matter so much, 
as he can easily come down and find out where he is. 



Night Landing 

Landing at night is the most difiicult part of night fly- 
ing. The pupil should never attempt any kind of landing 
except the straight glide. "S'' turns at night are danger- 
ous, and spirals are quite unnecessary. He should start his 
straight glide into the aerodrome from a couple of miles 
away, with his engine on slightly, very much in the same way 
as he would attempt to land in a small field in daylight. He 
will thus half fly, half glide towards the aerodrome. When 
he thinks he is within 30 ft. or 40 ft. of the ground on the 
near side of the aerodrome, he must shut off his engine 
completely, but he must not put his nose down. Instead, he 
should keep the control lever in exactly the same position 
as with the engine doing about half its normal number of 
revolutions, as was the case on the descent. He should use 
the lights at the short arm of the L at the end of the 
aerodrome as the best means of judging the height, and, at 
the same time, he must keep well away from the lights and 
the long arm of the L down which he is landing, and which 
gives him his distance. If he does not keep away from them 
he will not be able to see them. He should start flattening 
out early, but should do so gently and gradually. If he does 
not touch the ground when he thinks he ought to, he should 
pull the control-lever right back, but not so as to balloon, 
and await the bump. 

If he does not hit the ground by the time that the 
third flare is passed, he must switch on and open up his 
engine again to make another circuit. It is advisable to land 
short rather than over, the ideal spot for landing being 
about the second flare. A landing should never be made 
with the engine on, as this increases the speed of the ma- 
chine. People standing near the flares will give him some 



204 PRACTICAL FLYING 

idea of his height ; but this is not so accurate as that g^vei 
by the landing flares at the end of the ground. 



Night-flying Equipment 

A few words on the equipment of the night-flying ma 
chine may be useful. The electric-lighting outfit for thi 
instruments should be duplicated throughtout, two lights he 
ing fitted to each instrument and the switch duplicate 
The instruments themselves should have the figures paint 
,with luminous paint. 

An electric launching tube complete with battery and t\v 
parachute flares should be taken in case of a forced land 
ing. The tube may be conveniently fitted between the pilot'l 
legs, and a stick should also be carried to poke the parachute 
flare through the tube in the event of it sticking. If he hai 
to make a forced landing, he must remember that the wine 
will blow the parachute flare in a certain direction; there 
fore, he must let off the flare at a height of looo ft. or so 
outdistance it, and then turft and land into the wind againsl 
it. 

Holt's wing-tip flares are often fitted, but must be placed 
so that there is no chance of them setting the wing on firei 
Sometimes the wing tips are made of aluminium to preven 
this. Flares burn for 60 seconds, and can be switched on a 
a height of 1000 ft. Some machines are arranged with 
series of electric lights and powerful reflectors along aii( 
under the leading edge of the wings, the pilot being able t( 
control their exact position by wires, so that he can tun 
them down when he is near the earth and see what the 
ground is like. On some pusher machines a system of il 
lumination is fitted on the under-carriage. 

It is important that the propeller should be painted blad 
so that the light is not reflected on it, and does not dazzi 
the pilot's eyes when landing. Any bright parts of a ma 
chine should also be painted black for the same reason 
Wings, fuselage and tail are often painted black for this rea 
son, and also to prevent the machine being seen by enem} 
aircraft. 



AERODROME LIGHTING 



' Setting Out an Aerodroine 

The setting out of an aerodrome for night landing is a 
tery important matter. The petrol flares used to illuminate 
|he ground are placed in the form of the letter "L," gen- 
pJErally with the long arm lying into the wind. In certain 
ijcircumstances it may be placed slightly across wind, as, for 
instance, if there is a better entrance to the aerodrome in 



atat*Utt If <in%iitd. 



X*. 



Fewer It^Mj can be vjsd \f nKcejranj 
CrajfOj indfccAc ^itioo of Rati; . 50^*5 a^art 



Setting out a night landing ground. The petrol flares are in buckets 

and arranged at intervals of 50 or 100 yards. The tail of the 

L-shape indicates t^e limit of good landing ground, and also the 

direction from which the wind is blowing. 

that direction and the wind is only hght. The short arm 
always gives the pilot the far end limit and the best area in 
which to land, the length of this between the flares being 
about 75 yds. The distance between the flares on the long 
arm is 50 yds., the number of flares used depending on the 
length of the aerodrome. It does not matter whether the 
long arm is placed to the right or the left of the short arm. 



806 PRACTICAL FLYING 

but it is generally arranged to act as a guard against such 
obstacles as trees, houses or sheds when they border the 
aerodrome. Different aerodromes can be recognised at 
night by the different distances adopted between 3ie flares. 
At the two near comers of the aerodrome, i.e., where the 
pilot is to come in, two searchlights are sometimes ar- 
ranged with their beams converging at a point about one- 
third up the line of flares, which is the proper place for a 
pilot to land. It is a good plan to place a high pole, with a 
row of electric lights down it, at the near side of the aero- 
drome (but not so as to interfere with the pilot), to give 
him an idea of height, while, a bonfire 500 yds. or 600 yds. 
away, to illuminate the country and obstacles in front of 
him when finishing his glide, is also of assistance. All 
lights should be shaded so that their glare should not 
dazzle the pilot when landing. The illustration (page 205) 
shows how to set out an aerodrome for night flying. 



Night Flying Tests 

A prospective night pilot is seldom given any dual con- 
trol for night flying. His instructor can tell by his day- 
light flying if he is likely to make a successful night pilot, 
although it does not follow that because a pupil is only a fair 
daylight pilot he will be no use for night flying. He is gen- 
erally considered fit for night flying, under moderate con- 
ditions, if he can make six or ten successful landings and 
attain a height of 6000 ft. in the dark. He must familiarise 
himself by daylight with the aerodromes equipped for night 
flying where he may have to land. He must possess a good 
knowledge of the country and be familiar with those parts 
of it which are open, and those which are wooded or other- 
wise dangerous. He can acquire this knowledge by moon- 
light nights as well as by day. 

If an engine fails on a dark night, some people consider 
that the safest place to come down is on water, where the 
machine can be pancaked. 

When flying at heights of, say, 2000 ft., navigation lights 
of red on the left wing and green on the right, with a white 
one on the tail, can be used so as to avoid other machines. 



CHAPTER XII 

The Growth of Confidencje. — A Word Both to Instructors 

and Pupils 

ALTHOUGH an instructor cannot make a good pilot 
out of an unsuitable pupil (as a pilot is born and not 
made), he can prevent a moderate pupil from be- 
coming a moderate pilot by unwise actions. The art of in- 
structing lies in getting the best out of the available ma- 
terial at one's disposal. For instance, out of 20 pupils, two 
may turn out first-rate pilots, four distinctly above the 
average, six may give up aviation before they have com- 
pleted their training, and the remainder will be in the 
average run of pilots. 



Instilling Confidence 

A good instructor will be able to decide in the early stage 
of tuition which of the 20 pupils are likely to be useless as 
aviators, and the sooner that they are got rid of the better 
for both instructor and pupil. If they hang on, disliking 
flying all the time, yet being afraid to acknowledge it, a 
tremendous amount of time and money is wasted upon their 
tuition. Not only that, but it is more than likely that they 
will inspire similar feelings in some of the other pupils, with 
the result that others, who, had they not been subjected to 
this baneful influence, would have made aviators of mod- 
erate skill, may also become nervous and lose their original 
keenness. 

The growth of confidence in a pupil is one of the most 
important points which the instructor must study. He must 
try and inspire the pupil with confidence in himself as in- 
structor and in hi» judgment of the pupil's own capabilities ; 
while later on, when the pupil has flown solo, he must 

207 



208 PRACTICAL FLYING 

study the pupil's own confidence in himself. For this rea- 
son the pupil's first solo is of the most vital importance, and 
he should not be sent up unless he feels confidence in him- 
self. Let the instructor remember that an hour's extra 
dual-control work — which may make all the difference be- 
tween a crashed machine, an accident to the pupil, with the 
possibility of the latter resigning afterwards, and a first-rate 
pilot — is always worth the time and trouble expended. 

Steady Progress 

As the pupil advances in his course he can be sent up for 
longer and higher flights, the call upon his capabilities being 
gradually yet surely increased. Every time the pupil comes 
down after successfully doing something in the air that he 
has never done before, his confidence in his own abilities 
will have been increased. It may have been that he has done 
a spiral for the first time, or gone up in buriipy weather, or 
climbed a few thousand feet higher than he had ever done 
before; but in every case the growth of confidence will be 
there, and it should be the instructor's work to study it and 
to make the pupil make the best advantage of it in pushing 
his training ahead. 

On the other hand, a pupil should remember that a good 
instructor will probably know much more about his capa- 
bilities as an aviator, at any rate in his early stages, than he 
does himself. The instructor can tell after a few days 
which pupils are keen and which are not ; and here it may 
be repeated that a pupil who, after a few hours dual flying, 
decides that he does not like the work, had better say so and 
resign at once, rather than continue to waste his own and in- 
structor's time pretending that he does. There is no dis- 
grace in owning up to a feeling of nervousness in the air, 
and if more pupils did this as soon as they felt certain they 
would never make aviators, it would save a great deal of 
time and trouble. A first-rate instructor will generally turn 
out first-rate pupils, and vice versa ; so that a nervous pupil 
may possibly be made much worse by a nervous instructor, 
whereas if he were sent to an experienced pilot, who would 
allow him to do anything he liked in the air, he might 
overcome his nervousness. 



ADVANTAGES OF PRACTICE 209 



After a Crash 

Sometimes a pupil, in the early stages of solo work, has 
an accident and loses confidence in himself. It may pay to 
send him away for a few days' rest and change of scene, so 
that he cannot brood over the crash ; but if he is of a certain 
temperament, even this will not cure him, and he may have 
to resign altogether. 

Another type of pupil would not be affected at all in the 
same circumstances, but would want to go up again at 
once and make good the fault he had just committed. 
Probably the age of the pupil is largely responsible for this 
difference in temperament; a young and not yet fully-de- 
veloped pupil might be permanently frightened by a crash 
which an older and more experienced man would think 
nothing of. 

The More Practice the Better 

It is a very curious fact about aviation that the more 
one flies the less one minds it, and the less one flies the less 
one feels inclined to, so that it rests largely upon the pupil 
himself to go ahead. If he can overcome his apprehensions 
and master them, he will feel extra confidence, and the next 
time he will not find quite so much difficulty in forcing him- 
self into the air. Eventually, if he repeats the process a 
sufficient number of times, he will think as little of mak- 
ing a flight as getting into a train or taking a taxi. 

Recreation and, if possible, a change of scene are use- 
ful in getting the best out of pupils. It is a bad thing when 
an accident has taken place for pupils to be able to con- 
gregate and discuss all the details among themselves. It 
would be far better if they were able to go away and play 
a game of football or cricket, and so forget the accident, 
otherwise the less keen and stout-hearted among them will 
begin to brood, and, possibly, in the end, decide that they 
had better not continue with their course. 

Some pupils become nervous after they have done several 
hours solo work in the air. This may be due to something 
happening to them in the air which they do not under3tand. 



210 PRACTICAL FLYING 

or else it may be brought on by their being pushed forward 
too rapidly. A rest, in the latter case, may be advisable, 
when they may return to their work with all their original 
keenness. It all comes back to the original question, that 
it rests with the instructor as to what course he should ad- 
vise with reference to any given pupil. A course of action 
with one may prove fatal to another, hence the need for a 
careful study of the individual pupil's character and cap- 
abilities. 

Dual Control in Rough Weather 

Flying in bumps is a difficulty with some beginners. 
Often it is a good plan for the instructor to take up a pupil 
in a dual-control machine in bumpy weather and to allow 
him to fly it so as to discover for himself that there is no 
particular danger in bumps, although the feeling of security 
and conrol may not be so great as it is in calm weather. 

A point of great importance is to get the pupil over his 
first two or three hours solo work as quickly and as safely 
as possible. If his first few landings or get-off s are not 
sufficiently good, the instructor should explain to him his 
faults, and, if necessary, give him more dual-control. If 
bad weather intervenes between the pupil's first few solos, 
more dual-control work should be given to allow the pupil 
to get his eye in again. For this reason, especially in winter 
time, the pupil should be pushed forward over his earliest 
stages of flying,* so that he can gain the necessary con- 
fidence in himself as soon as possible, otherwise his course 
of instruction under bad weather conditions may be pro- 
longed for months instead of weeks. 



Advance Dual Control 

Even when a pupil can fly a machine solo, he may teach 
himself a number of bad faults, and for this reason an in- 
structor would be well advised to take up the pupil from 
time to time and test his flying. Much more can be done 
nowadays by means of dual-control work than was thought 
possible in the early days. Pupils can be taught to do 



DURATION OF TUITION 811 

vertical turns and spirals, loops, spinning nose dives, cart- 
wheels, stalls, etc., but the principal point to remember is 
that the object of giving advanced dual-control instruction 
after the pupil can fly solo is to secure accuracy in flying, 
and to prevent the pupil from getting into careless ways of 
handling his machine in the air. Careless or bad flying 
may not matter much on a heavy and soggy elementary ma- 
chine; but if the pupil allows himself to adopt the same 
sloppy methods on a machine of a more sensitive type, he 
will soon find himself in difficulties. Hence the importance 
of accurate flying even in the earliest stages. Another 
point in favour of giving a pupil advanced dual control is 
that this system has been found to increase his confidence 
in the machine in the air. If an instructor shows a pupil 
how to get out of practically any position, the pupil will be 
able to save himself if he ever finds himself in a similar 
position. Not only that, but the pupil will possess the neces- 
sary knowledge and confidence to be able to put the machine 
in those positions, besides being able to get it out of them. 
AH this means that he will be a far better pilot. 



When a Pupil Can Fly 

A pupil should be able to fly an elementary school ma- 
chine solo after, say, five hours dual-control instruction. 
He will then do 20 or 30 hours solo on various types of 
machines, with a little dual control in landings on the more 
elementary types. If he shows some aptitude for flying 
he will, at the end of his 15 or 20 hours solo, be put on to 
"faster and faster machines of the scout type, in which case, 
of course, no dual control is given. The length of his 
course of instruction depends on the weather. In the 
summer time it may take him two or three months to 
qualify as a scout pilot; whilst in the winter time it may 
take him much longer. Naturally, the keen pupil will get 
ahead of those who are less enterprising, with the result 
that he will benefit accordingly. It rests with the pupil to 
improve his own flying after a certain point. The great 
thing is constant practice. 



212 



PRACTICAL FLYING 



The Time Taken in Learning 

A word to instructors on the quickest method of teach- 
ing pupils to fly may be of value at this point. If the pupil 
can be taught to fly in the air in, say, from 40 minutes to 
50 minutes, the get-oflFs and landings may take him a fur- 
ther 3 hours or 4 hours. It is therefore advisable to get 
the pupil on to get-offs and landings as soon as possible. 
He will require more instruction in landing than in taking 
oflF. Therefore, to speed up instruction, the more landings 
the instructor can put in in a given time the sooner will the 
pupil become a pilot. With this in view, some instructors 
prefer to make large circuits of an aerodrome, landing, 
perhaps, four or five times per circuit and switching on 
again without stopping the machine. Others may do 
straights and land two or three times in each straight. A 



NoZFUsht 




Plan of aerodrome and landing ground. Suggested arrangement of 

main aerodrome and subsidiary landing grounds at a distance, of a 

few miles from headquarters. This arrangement should facUitate 

landing practice for a large number of pupils at one time. 



POINTS FOR INSTRUCTORS 213 

third plan is to make small circuits, rising to a height of 
several hundred feet, and then land in the same place again 
and again. The greatest number of landings can be got 
in in a given time by the first method, but this necessitates 
comparatively calm air, as otherwise the landings in the 
course of the circuit would have to be made across and 
down wind. A point that should be noted is that a land- 
ing from a low height, say, loo ft., does not teach the pupil 
much, as the landing he should practise should be prefaced 
by the ordinary glide of several hundred feet. There is a 
good deal of difference between landing from a height of 
ICO ft. and from a height of looo ft., and if the pupil has 
only been taught the first, he will probably go hopelessly 
wrong when he attempts the second. 



Thoroughness in Instruction 

An instructor should always remember that a pupil must 
be taught every bit of flying that is necessary in handling 
a machine, i.e., starting up, taxying, taking off, climbing, 
flying level, turning to right and left, shutting off the en- 
gine, gliding and landing. Furthermore, it may be neces- 
sary for an instructor to show a pupil what to do in 
emergencies, i.e., if he bounces through failing to flatten 
out, or if he should flatten out too soon or too much ; then, 
when the pupil is faced with these situations, he will do 
the right and not the wrong thing. 

When a very large number of pupils are being trained at 
the same school, it will prevent congestion of the air and 
aerodrome if a number of small landing grounds are se- 
lected at a radius of several miles from the air station. It 
is far easier for 36 pupils to be given landing practice at six 
different fields than for the whole 36 to be taught on the 
same small patch of aerodrome. The accompanying sketch 
gives an idea of how this suggestion might be carried out. 
(See opposite page.) 



CHAPTER XIII 
The Medical Aspect of Aviation 

By 

H. GRAEM ANDERSON, M.B., Ch.B., F.R.C.S. 

Temp. Surgeon R.N., Attached R.N.A.S., Surgeon to St. Mark's 

and the Belgrave Hospitals. 

TO fly, an individual must be physically and tempera- 
mentally fit; especially is this so during instruc- 
tion in the first 20 hours of solo flying. A pupil 
should not conceal any disease, and should he feel physically 
and temperamentally unfit, he should inform his instructor. 

Many pupils remain silent and do not confess their dis- 
inclination to fly, fearing that their instructor or other pupils 
will taunt them with having cold feet. "It is certain that 
an aviator's disinclination to fly must have its basis upon 
some temporary defect of body or mind, and, without being 
unduly sensitive or timid, he should realise this and over- 
come the cause rather than tempt Providence by running 
the danger of overtaxing his power." This quotation from 
another writer on the subject applies most particularly to 
pupils. 

Flying is a question of an active, well-balanced, decisive 
mind and a series of sound and quick reflex actions. 

These reflexes are: — 

1. Visual. 3. Tactile, 

2. Auditory. 4. Muscular. 

5. Balancing. 

The Visual Reflex 

( I ) The visual reflex consists of the impressions carried 
through the eyes to the brain, and from there down to the 
muscles of the hands and feet; e.g., the pupil sees a wing 
tilted up to the right ; this impression is transmitted through 

214 



REFLEX ACTIONS 216 

the eyes to the brain, there recorded, and a decision made 
which is sent down to the muscles of "the hands, and the 
control lever is pushed over to the right. The normal time 
for the visual reflex action to occur is 20-iooths of a second. 
This is the reflex action, the most important and most used 
by the aviator. It is essential that all parts of this reflex 
are in good working order. Thus it can be seen how im- 
portant is good vision in flying. I consider that no person 
should take up aviation unless he has full normal vision 
in both eyes. 

The Auditory Reflex 

(2) The auditory reflex consists of the impressions 
carried through the organ of hearing — ^the ear — ^to the 
brain, and from there to the muscles of hands and feet ; e.g., 
the sound of the engine missing is conveyed to the brain 
through the ear, recorded there, and a decision immediately 
made to look for a good landing place, land and repair 
the defect, is transmitted to the muscles of action of eyes, 
head, feet and hands. The normal time for the auditory re- 
flex is 14-ipoths of a second. This reflex is next in impor- 
tance to the aviator, and it is essential that he should have 
good hearing. Wax is apt to accumulate in the ears and 
cause deafness. This deafness comes on gradually, but is 
usually made much worse after washing or swimming, when 
water gets in the ears and expands the wax. Lack of good 
hearing may lead to disastrous results. For example, when 
starting up the engine, should the pilot fail to hear— or mis- 
interpret — the words ''Contact!" or "Switch off!" when 
given by the mechanic who is swinging the propeller. 



Tactile and Muscular Reflexes 

(3) The tactile and (4) the muscular sense reflexes are 
the impressions conveyed through the nerve endings in the 
skin and muscles to the brain, and from there down to the 
muscles of the hands and feet. For example, the pilot feels 
a bump, which sensation is conveyed from the skin and 
muscles to the brain, recorded there, and the decision sent 



816 PRACTICAL FLYING 

down to the muscles of the hands to correct the effects of 
the bump. The normal time for the tactile reflex is 14- 
looths of a second. 

The Balancing Reflex 

(5) The sense of balance or equilibration is received 
from the semi-circular canals, three in number, on each 
side, encased in bone, and situated behind the ears. These 
canals contain fluid and fine nerve endings. When the pilot 
and machine are off the level, either fore and aft or laterally, 
these little canals send impressions to the brain, and from 
there correcting impulses are sent down to the muscles of 
the hands and feet. 

All these reflexes are slowed down or disturbed if the 
pilot is physically or temperamentally unfit from any 
disease, worry, fatigue, or after excesses in alcohol, etc. A 
slow reflex action, the delay of a second or part of a second 
in correcting an error in the air or in landing, may mean 
all the difference between a crash and safety. Thus, to pre- 
serve these reflexes, one sees how important it is to keep 
the body and mind in good condition during the tuition pe- 
riod of flying. 

Drinking and Smoking 

Alcohol is better avoided altogether, and, similarly, ex- 
cess in smoking, which may cause palpitation, faintness and 
double vision. Most aviators smoke too much. Diet should 
be generous and nourishing, as there is a good deal of nerve 
strain and wear and tear of the nervous system during this 
period. Flying when hungry is to be avoided, as faintness 
may occur in the air. Proper sleep is most important, and 8 
hours sound sleep in the 24 hours should be obtained. Well- 
regulated physical training is of great value, and pupils 
should be afforded every recreation of mind and body at an 
air station. 

With regard to the psychology of flying, or the study 
of the sensations in the air, it has been found from an 
analysis of 100 confessions of pupils after their first solo 
flights that the mind is so occupied in paying attention 
to flying, watching instruments, controls, etc., that fear has 



OVER-CONFIDENCE 817 

rarely time to assert itself, at least, not enough to disturb 
their flying. Later on, a pupil is apt to become over-con- 
fident, and this must be guarded against. Coolness, level 
judgment and quick reflex actions are the secrets of suc- 
cess in flying. The fact that aeroplanes are now so im- 
proved and structurally strong that there is little or no 
danger of anything giving way in the air, should reassure 
pupils, who sometimes are distressed with this thought 
whilst in the air. 

Pupils should always, strap themselves in before getting 
off the ground, and they should become familiar with the 
fixing and unfixing of the belt. Belts should never be 
undone in the air. Unless belted, it is possible that in a 
bump, dive, or in faintness an aviator might fall forward on 
to the control lever with disastrous results. It is advisable 
for all pilots to carry a stout knife and a wire cutter in the 
outside pocket of the fl)dng coat, so as to be able to cut 
themselves out of a crashed machine. (See page 183.) 

What to Wear 

Safety helmets should be worn by pupils, as, in the event 
of a crash, they prevent injuries to the head and ears caused 
by wires and broken struts. The helmet should fit prop- 
erly and not be easily dislodged from the head so as to slip 
forward. The ears must be well protected in front so that 
there is no rush of air straight across the orifice of the ear. 
A good helmet has a little roll of leather in front of each 
ear to deflect the air stream, thus enabling the pilot to hear 
well and also to prevent any damage to the ear drum. 

Goggles should always be fitted with non-splintering 
glass, such as Triplex. Plain glass goggles should never be 
used, as in the event of their breaking serious injury might 
be caused to the eyes. 

Gloves of leather lined with lambswool are the best for 
warmth and do not diminish the touch. The gauntlets 
should not be too stiff or too wide. It is better to wear the 
gauntlet inside the coat cuff, the latter being drawn tight 
by a strap. Close and tight-fitting gloves should be avoided. 

Soft leather field boots lined with lambswool and thick 
woollen socks keep the feet and legs warm. Rubber boots 



y^ 



/ 



818 PRACTICAL FLYING 

should not be used, as they do not give much warmth and 
are apt to slip on the rudder bar. 

The body clothing for flying, of course, varies for winter 
and sunmier. No articles should fit too ti^tly. Woollen 
material is the best, as its interstices allow of a layer of 
warm air next to the skin. Leather outer garments are 
usually worn. 

Most aviators fly with the mouth slightly open. Pupils 
should see that their teeth and gums are in a healthy state, 
otherwise any local disease therein is apt to be increased by 
the cold and rush of air. 

« 

Preventing Frostbite 

Should a pupil have to do a height test in winter, a good 
method of preventing frostbite — or should the skin be sen- 
sitive — is to smear the face and hands with a thin layer of 
vaseline. This prevents heat loss from the skin. 

Air Sickness 

There are two forms of air sickness. One, which is. akin' 
to sea sickness, and due to the rolling and pitching of the 
aeroplane in bumpy weather, is very rare, but now and 
then one finds an individual liable to this ailment. Of 
course, a pilot, by doing steep spirals and switchbacks, may 
produce this form of sickness in a passenger. The other 
form of air sickness is due to height eflfects, and is better 
named "altitude sickness." It occurs at height of 10,000 ft. 
and over, and is caused by the rarefied atmosphere and lack 
of oxygen. After passing 6000 ft. the breathing, and pulse 
rate become quicker. Over 10,000 ft. the cold is extreme; 
slight buzzing in the ears, difiiculty in hearing, headache, 
fatigue and torpor may occur. On descending rapidly, the 
deafness and buzzing in the ears become more acute, and 
severe earache may be felt. The headache continues for 
some time after landing and sleepiness is very marked. To 
guard against these effects when going to great heights, 
especially for any length of time, oxygen should be carried 
and inhaled slowly as a preventive. 



FLYING INSTRUCTION NOTES IN BRIEF 

General and Condensed Hints in Definite Stages for the 

Guidance of Pupils 

Stage 1. — Before Instruction — General 

I. — Find out why a machine flies and leam to understand 
what happens when you get off, fly level, dive, turn steeply 
or gently, and land. 

2. — Study the control levers and their effect when moved 
on the controlling surfaces (rudder, elevator and ail- 
erons) of the machine you are going to fly. 

3. — Find out how the switch, petrol and oil taps, throttle 
and fine adjustment work. 

4. — Find out how the instruments work and what they 
are for ; air speed indicator, height recorder, engine revolu- 
tion counter, compass and sideslip indicator. 

5. — Leam all about the details of construction of the ma- 
chine and engine. 

6. — Practise swinging the propeller. 

7. — Practise sitting in the machine and working the con- 
trol levers as if you were flying. 

8. — Find out the correct number of revolutions at which 
to run the engine, and the climbing, flying level, and gliding 
speeds of the machine. 

9. — If there are any points that puzzle you, ask your 
instructor to explain them. 

10. — ^When an engine or machine gives trouble, find out 
the cause and remedy. 

II. — Obtain a map of the country round the aerodrome 
and study it, so that you can pick up your bearings in the 
air. 

Stage 2. — Early Instruction 

I. — Never keep your instructor waiting. Be ready with 
flying gear, speaking tubes, gloves, cap, goggles, etc., to take 
your place in the machine. 

219 



««0 PRACTICAL FLYING 

2. — ^Always be punctual at the shed. 

3. — Before going up, fasten your safety belt. 

4. — ^Get a clear understanding with your instructor as to 
what signs or signals he will make when you are to take 
control, let go, fly stfraight, or turn. 

5. — When given control, do not hold too tightly, but do 
not be frightened of working the controls when necessary. 
You can fly the machine with one hand and two feet. 

6.— Try and get the "feel" of the machine as soon as pos- 
sible. 

7. — ^Always look out in front of you on the horizon. It 
gives you the best guide as to when you are Qying hori- 
zontally or longitudinally level. 

8. — If you don't understand, always ask your instruc- 
tor to explain anything he has told you, or any point that 
has occurred to you during your flight. 

9. — ^To fly horizontally level, keep the nose of the machine 
on the horizon. To climb, keep the hose above the horizon, 
and to descend put the nose below the horizon. 

10. — To fly laterally or horizontally level, keep the under- 
side of the top plane parallel with the horizon. 

Stage S. — Flying Level and Turns 

I. — ^To fly straight, fix your eye on some landmark on the 
ground ahead of you, such as a village or wood, or a cloud, 
and steer the machine towards it by means of the rudder. 

2. — ^The position of the control levers is only relative. 
If you find that the machine is flying to the left in still air, 
with the rudder central, you must give a little more right 
rudder to fly straight. 

3. — Learn to fly by sight and feel. Only use your in- 
struments to verify occasionally the accuracy of your flying. 

4. — Don't be alarmed at "bumps," but correct them 
quickly and firmly but not jerkily. 

5. — In turning, keep the nose of the machine on the 
horizon. Then apply bank and rudder gently and gradu- 
ally in the direction you wish to turn. If your bank is too 
steep ease off the control lever. If your bank is too small, 
put on a little more by moving the control lever still further 
over in the desired direction. 



SUMMARISED INSTRUCTIONS 221 

6. — When straightening up after turning, move the con- 
trol lever slightly in advance of the rudder, and rather 
past the central in the opposite direction to begin with. It 
can then be moved back to central when the rudder is cen- 
tral and the machine horizontally level. 

7- — Learn to make gentle and gradual turns before at- 
tempting quick ones, which need more bank and greater 
accuracy. 

8. — If you are turning to the right and notice wind 
striking your left cheek, you are side-slipping outwards, so 
give a little more bank or take off some rudder. If the 
wind strikes your right cheek on a right-hand turn, you are 
side-slipping inwards. Remedy : more rudder or less bank. 

9. — In making steep turns over 45 degrees, first bank 
and rudder in the desired direction. Trim the nose of the 
machine to the horizon by easing off bottom rudder, and 
make the machine turn by pulling the stick back towards the 
opposite elbow. 

ID. — ^As the machine will be on its side relative to the 
horizon, the rudder acts as elevator and the elevator as 
rudder. 

II. — To come out of a steep turn, move the control lever 
still further over in the opposite direction and then forward 
and back to central position in a semi-circular movement. 
If you centre the control too soon, the machine will not 
be flying horizontally level. If you give opposite rudder 
too early, the nose will go up and you will side-slip inwards. 

12. — In climbing and gliding turns, the nose of the ma- 
chine must be kept above and below the horizon respectively, 
according to the correct climbing and gliding angle. The 
same rules re making and coming out of these turns apply 
as in ftying level turns. 

Stage 4. — Getting Off 

I. — See that there are no loose articles in the passenger's 
seat that can foul the controls. 

2. — See that the chocks are under the wheels. 

3. — Fasten your belt and set the height indicator to "o." 
Hold the control lever back. 

4. — ^Turn on petrol and see that the switch is off. Pump 
up pressure if necessary. 



228 PRACTICAL FLYING 

5. — Open throttle or fine adjustment and close air to suck 
in. 

6. — Qose throttle or fine adjustment, let go air lever, and 
give contact when the mechanic at the propeller is ready. 

7. — Note the formula adopted for starting up the pro- 
peller, i.e., "contact," "switch off," as said by the mechanic 
and repeated loudly by the pilot. 

8. — Don't run the engine more than is necessary. Warm 
up from cold gradually and throttle down again as soon as 
maximum revolutions are obtained. 

9. — Wave your hand over your head to mechanics to^ 
withdraw chocks, and see that they have let go. 

10. — Taxy out slowly with stick rather back of central 
position. 

II. — Turn by using the rudder with a little extra engine. 

12. — Get off into the wind. 

13. — Get under way gradually, i.e., open up the engine 
steadily and not with a jerk. Some engines give their 
correct revolutions when the throttle is partially open. 

14. — Push the stick forward as the machine gathers 
speed, and then ease it back when the tail is up and you 
think you have attained sufficient flying speed on the 
ground. It is safer to get off too late than too early. 

15. — ^When it is difficult to hold the machine on the 
ground, the control lever can be eased back, and the machine 
will take the air. Don't pull the lever back with a jerk. 

16. — As soon as the machine is in the air, ease the con- 
trol lever forward, so as to allow the machine to gather 
more speed. Then climb steadily to the required height, say, 
1000 ft. 

17. — If the machine tends to swing sideways when get- 
ting up speed on the ground, rudder in the opposite direction 
and counteract the swing before it develops. 

Stage 5. — Landing 

I. — Close the throttle fully and put the nose of the ma- 
chine down to the correct gliding angle, i.e., with the nose 
the correct amount below the horizon. The speed should 
be slightly under flying level speed. 

2. — Make a straight glide. 



SUMMARISED INSTRUCTIONS 828 

3. — ^When approaching the earth, watch the ground 30 
yards in front of the machine. This is very important 

4. — Don't be disheartened if you fail to make a good land- 
ing to begin with. You need more practice. 

S.-^The ideal flatten out starts with the control lever in 
the gliding position about 30 feet from the ground, and 
ends with the control lever right back in your chest as the 
machine touches the ground. 

6. Try and keep the wheels of thie machine off the ground 
as long as possible. 

7. — The machine must not lose its flying speed until it is 
a few inches from the ground. 

8. — If it loses its flying speed too early, it will pancake, 
that is, you have flattened out too soon, and you will flop 
instead of gliding to earth. 

9. — If you try and lose your flying speed too late, you 
will fly into the ground and bounce. 

10. — ^A good landing is all a matter of an accurate eye 
and a fine touch. No sudden or jerky movement is re- 
quired. 

II. — If you bounce badly, use your engine, make another 
circuit and try again. 

12. — To begin with, the ground will seem to be coming up 
very fast towards you, but you will soon get used to it. 

13. — In landing or getting oflF cross wind, keep the wing 
nearest the wind down, so as to eliminate a crabbing motion 
over the ground by side-slipping into the wind. 

Stage 6. — Taxyino 

I. — Taxy slowly, with the control lever well back, to keep 
the tail on the ground. 

2. — ^Tum the machine by means of the rudder. 

3. — Look where you are going, and go dead slow over 
bad groimd or ruts. 

4. — Use your motor well throttled down, and don't open 
up or throttle down in jerks. Don't "blip" the engine un- 
less you have been taught. 

5. — When machines are getting off or landing near you, 
keep stationary so as not to baulk them. 

6. — Don't turn quickly on the ground, as this wears out 
the tail skids and twists the tail. 



224 PRACTICAL FLYING 

7. — In taxying down wind, keep the control lever for- 
ward, so that the wind on the elevator keeps the tail down. 

8. — In taxying in a strong wind, tell off two mechanics to 
hold on to the wing tips, so as to prevent the machine lifting. 

Stage 7. — The First Solo 

I. — Don't be in two much of a hurry. Fasten your 
safety belt and see that your crash helmet is secure. 

2. — Clearly understand your instructor's final advice 
as to where you are to get off and land, how long you 
are to stay up, and at what height you are to fly. 

3. — See that your motor is doing its correct number 
of revolutions on the ground, and when you have attained 
the desired height throttle down to fly level. Set the height 
indicator to "o." 

4. — Give the proper signal to the mechanics to withdraw 
the chocks by waving the hand over the head, and wait a 
moment or two for them to get clear. 

5. — See that there are no machines getting off or land- 
ing which may baulk you in starting. 

6. — Remember the instructions on getting off. (Stage 4.) 

7. — ^Don't go out of gliding distance of the aerodrome, but 
make full circuits, and don't cut across the aerodrome or 
go the wrong way round. 

8. — Look out for other machines in the air. 

9. — You will find that the machine will climb much more 
quickly solo than dual, so don't get too high before you 
realise it. 

ID. — If the weather is doubtful, look out for rain or 
thunderstorms or banks of mist, and come down at once 
if they approach the aerodrome. 

II. — If you are lost, come down at once, but fly low, 
say, 500 feet, round the field you have selected to land in 
before doing so, in order to see that it is suitable for the 
purpose. Then find out where you are and return home. 
If you have damaged the machine, telephone immediately 
full particulars to the aerodrome. 

12. — When you decide to land, make a straight glide into 
the wind. 

13. — Remember the instructions on landing. (Stage 5.) 



SUMMARISED INSTRUCTIONS 225 

14. — ^If there are machines on the ground when you want 
to land, make another circuit till the course is clear for you. 

15. — You should know the whereabouts of bad ground on 
the aerodrome, and must avoid it. 

16. — If you bounce badly, make another circuit and try 
again. 

17. — Don't point the machine at sheds or woods when 
landing, as you may overshoot and run into them. 

18. — If you see that you will overshoot the mark, make 
another circuit and try again. 

19. — ^Don't turn under 500 ft., and remember the instruc- 
tions on turning. (Stage 3.) 

20. — Don't get off facing woods or sheds unless you have 
plenty of room to gain height before crossing them. 

21. — Report to your instructor after the flight, and listen 
carefully to criticisms, so that you can learn how to avoid 
such mistakes another time. 

22. — Don't get over-confident. Take just as much care 
with your solo flights as you did with your first. 

23. — Remember any special ground signs that are used 
to call all machines in from the air. 

24. — ^Always report any defect in the machine to your in- 
structor. 

Stage 8. — Cross-country 

I. — ^Work out your course accurately and carefully. 

2. — Spend half an hour studying the map and the course 
you have been set. 

3. — See that the engine, machine and instruments are in 
good working condition. 

4. — Take the necessary tools, spare parts and money with 
you. An identification card is advisable. 

5. — Find out the distance of the flight, and take your time 
of departure so that you have a check on your journey. 

6. — See that the petrol and oil tanks are full. 

7. — ^Take nothing for granted, but go over everything 
yourself. 

8. — Find your way by using the compass and map in con- 
junction. Avoid clouds. 

9. — As soon as you are lost, circle round some well- 
defined landmark on the ground about where you should 



2S6 PRACTICAL FLYING 

be judging by your time out and speed, and try and recog- 
nise it on the map. If you cannot, come down. (See in- 
structions on Stage 7.) 

ID. — Always note the direction of the wind by smoke, 
or by what direction it was blowing when you last no- 
ticed it or at the start. You can also tell the direction of the 
wind by watching the drift of your machine. 

II. — If your engine fails suddenly, switch off, turn the 
petrol off, and put the nose down. 

12. — Select a field (grass for preference) free from ob- 
stacles, trees, houses, etc., and with length in the direction 
of the wind. A group of fields is preferable, as if you miss 
one you can land in the next. 

13. — "S" turns provide the best method of making cer- 
tain of hitting off the desired field. 

14. — But don't turn near the ground. 

15. — Aim at the near side of the field so as to give your- 
self the greatest run for landing. 

16. — Don't come down too fast, as if you hit anything 
after landing or while gliding near the ground your speed 
will cause a worse crash. 

17. — Don't land near railways or main roads for fear of 
telegraph wires,, which are hard to see. 

18. — Don't spiral down, as you may be facing the wrong 
way when you want to land. 

19. — If you crash, telephone the aerodrome, stating the 
full extent of the damage. 

20. — If you are able to continue the journey, take the 
fullest possible run in which to get off, and survey the 
ground ahead of you before starting. 

21. — You must pancake in soft plough, standing crops 
or woods, with your stick right back and tail down. 

22. — If after landing you see you are going to run into 
something, rudder away from it. You may remove the 
under-carriage, but this is better than smashing the whole 
machine. 

23. — If you are up late, come down before it is dark. 

24. — Peg the machine down for the night under the lee of 
trees, a hedge or house. 

25. — Cover the engine, propeller and pilot's seat with a 
tarpaulin or sacking. 



SUMMARISED INSTRUCTIONS 227 

26. — If the motor goes wrong, try and locate the fault, 
and if possible repair it yourself. 

27. — If your motor shows signs of gradually dying 
away, remember it is far easier to land with some engine 
than none, so come down and find the trouble. It may 
be a choked petrol supply or a faulty plug or two, or even 
loss of pressure in the petrol tank. 

28.- — Come down if there are signs of fog, heavy thunder- 
storms or snow. 

29. — Practise map-reading before going on a cross- 
country flight. This can be done on solo flights round the 
aerodrome. 

30. — In getting out of a small field it is best to "hoik" at 
the last moment and jump the hedge. 

31. — Never stunt near the ground. 

Stage 9. — Advanced Flying 

I. — Every time you go up solo try and do something you 
have never done before, i.e., go up higher, or for a longer 
flight, or in worse weather, or practise aerobatics. 

2. — First perfect yourself in landing on a mark with 
engine cut off. 

3. — For this, "S" turns, spirals and vertical banks with 
and without engine must be practised. 

4. — Practise climbing turns and stalling turns. The latter 
are performed by pulling the machine up on its nose and 
then banking and ruddering in the desired direction. The 
engine can be cut off during the manoeuvre. Modifications 
of this manoeuvre with the engine on result in cartwheels 
and Immelman turns in which the machine does an about 
turn. 

5. — In all aerobatics avoid too sudden changes of direc- 
tion of the machine, i.e., pull the machine out of a dive 
gently and gradually. 

6. — To zoom, fly level at full speed, and then pull the 
stick back. At the top of the zoom ease the stick forward. 

7, — A hoiked turn is a curving zoom, but you should 
know your machine, and practise this at 1000 ft. 

8. — To loop, put the nose down to 85 m.p.h., and pull the 
stick straight back into your chest. When over, cut out the 



228 PRACTICAL FLYING 

engine, and pull the machine out of the dive gently. The 
latter part of the pull back is quicker than the first in 
starting the loop. 

9. — ^To spin, cut out the engine, and stall the machine 
level with the nose on the horizon. Kick on rudder, and 
pull the stick right back into the chest. To come out, centre 
the rudder gently, and ease the stick forward. 

ID. — ^To roll, get up speed either with or without engine, 
kick on rudder, and pull the stick right back. 

II. — ^To turn very quickly, switch off momentarily, kick 
on rudder without any bank, which will pull the machine up 
and twist its nose round in the desired direction. She 
will get into a spin if not righted immediately. Then switch 
on. 

12. — To sideslip or partially glide sideways, switch off, 
put on bank in one direction and rudder in the other. The 
machine will glide sideways in the direction in which the 
stick is held. 

13. — The falling leaf descent is done with the engine off, 
and the stick held back in the pilot's chest. After she stalls, 
she can be allowed to gain speed, and then stalled again. If 
the engine stops, dive to restart it. 

14. — Diving is best done with the engine off. Put the 
stick forward, and hold it there while the speed increases. 
Pull out of a vertical dive very gradually. 

15. — Try all advanced flying at a height of 2000 ft. or 
3000 ft. 

16. — Practise sham flights and aerobatics with other 
pupils if your instructor thinks you are good enough. Prac- 
tise approaching machines unseen, and always take note 
of the machines in the air about you. 



GLOSSARY OF TERMS COMMONLY USED IN 

AVIATION. 

Aerobatics 

Aerial manoeuvre stunts. 

Aeroplane 

A heavier-than-air flying machine, supported by the 
action of air on fixed planes. 

Ailerons 

Hinged flaps let into the extremities of the main 
planes and operated by the control lever, to bank 
the machine and also to maintain its lateral level. 

AxLERONs, Balanced 

By connecting the ailerons of each wing, so that 
when one is pulled down and the other is pulled up 
the surfaces are made to balance. 

Airbrake 

A flap that can be let down so as to increase the 
resistance of the machine to the air. 

Air Pocket 

See "Pocket." 

Air Speed 

The speed of the machine through the air. 

Air Speed Indicator 

An instrument for registering the speed of the ma- 
chine through the air. 

Altimeter 

An instrument for indicating the height of the ma- 
chine from the ground where it started from. 

Angle of Incidence 

See "Incidence." 

Aspect Ratio 

The proportion of span to chord of a plane. 

229 



280 PRACTICAL FLYING 

Back 

A change of wind in an anti-clockwise direction, i.e., 
from E. to N. 

Backwash 

The disturbed air in the wake of a machine in 
flight. 

BALIiOON, To 

The upward glide of a machine near the ground 
caused by the pilot descending too fast and pulling 
the control lever back too much or too quickly. 

Bank, To 

To raise one wing for the purpose of turning. 

Bay 

The space enclosed by two struts and their upper 
and lower adjoining surfaces. 

Belt 

The safety strap which secures the pilot to his 
seat. 

Bessoneau 

A tent for storing aeroplanes which can be erected 
and dismantled in a few days. 

Biplane 

An aeroplane with two pairs of wings set one 
above the other. 

Bumf 

Slang term referring to small airships. 

Blip, To 

To switch on and off rapidly. 

Body 

That part of a machine which accommodates the 
engine, pilot, passenger and probably the petrol and 
oil tanks. 

Boom 

See "Tail Boom." 

Boss OF A Peopellee 

The centre portion by which it is attached to the en- 
gine. 






t 



GLOSSARY 231 

Bounce 
i,e The upward and forward movement of a machine 

which has struck the ground without flattening out 
sufficiently. 

r Beevet 

A certificate showing that a pilot has passed certain 
elementary flying tests and may be considered a 
qualified pilot. 
Bumps 

Disturbances or roughness in the air due either to 
changes of temperature, clouds or wind. 

Cabane 

The projecting arrangement of struts above the 

pilot's head on a monoplane to which the anti-lift 

wires are attached. 
Cabee 

Tail down. 

Cambee 

The maximum depth of curvature of the upper and 
lower surfaces of a wing. 

Caetwheel 

A particular type of aerial manoeuvre. 

Cell 

The whole of the lower surface of a plane and the 
whole of the top surface of the plane above it, with 
the struts and wires holding them together. 

Cellule 

The box-like rectangular compartments in a biplane 
formed by the upper and lower planes and the inter- 
plane struts. 

Centee or Geavity 

Centre of weight. 

Centee of Peessuee 

A line running from wing tip to wing tip, through 
which all the air forces on the wing may be said to 
act. 

Centee Section 

The centre cellule of a biplane where this cellule is 
made detachable from the wings. 



«8« PRACTICAL FLYING 

Chocks 

Wooden blocks placed in front of the wheels of a 
machine to prevent it moving when the engine is 
started. 

Chord of a Wing 

The distance between the leading and trailing edge 
of a wing. 

Cockpit 

The pilot's seat. 

Cold Feet 

A complaint, otherwise known as aerosthenia or 
nervousness of going into the air. 

Combustion Chamber 

The space between the top of the piston and the 
cylinder where the explosion of the mixture takes 
place. 

Compression 

The upward stroke of the piston which compresses 
the mixture in the combustion chamber. 

Conk 

The engine is said to "conk" when it fails. 

Contact 

Word used to denote that the switch is on. 

Control Lever 

Generally known as the "joy stick" or stick. A 
vertical lever controlling the fore-and-aft and lateral 
movements of the machine. 

Control Wires 

Wires connecting the rudder bar and control 

lever with their respective controlling surfaces. 
Cowl 

A sheet-metal cover generally fitted over or round 

the engine. 

Crash Helmet 

A specially-made flying helmet designed to save the 
pilot's head in case of a crash. 

Crash, To 

To smash the machine. 



GLOSSARY «88 

Dihedral Angle 

A machine is said to possess a dihedral angle 
when the wings rise upward from the centre of flie 
machine. 



Dive 
Dope 



To descend steeply. 



A preparation used to paint the wings in order 
to render them taut and weatherproof. 

Dope Can 

A metal syringe containing petrol for priming the 
engine. 
Drift 

The crabwise motion of a machine over the ground 
due to a side wind; also used to denote head re- 
sistance. 

Dual Control 

A system of levers and controls for the engine 
and riiachine, so that either the pilot or passenger 
can operate them. 

Elevator 

A hinged controlling surface, or flap, operated by 
the fore-and-aft movement of the control le^er. 
Always set parallel with the wings of the machine 
and generally behind them. Used to control the up- 
and-down motion of the machine and in steep banks 
to make the machine turn. 
Empenage 

The tail unit of a machine, consisting of rudder, 
elevator and fixed tail plane. 

Engine Bearer 

The metal framework or tubing to which the en- 
gine is fixed. 

Exhaust 

The upward stroke of the piston which drives the 
burnt and exhaust gas out of the combustion cham- 
ber. 

Explosion 

The power stroke of the engine. 



884 PRACTICAL FLYING 

Extensions 

Additional lifting surfaces added to the top 
planes. 

Factor of Safety 

Obtained by dividing the stress at which a body 
will collapse by the maximum stress it will be called 
upon to bear. 

Fin 

A fixed vertical plane generally fitted in front of the 
rudder to increase the stability of the machine. 

Flabes, Ground 

Waste soaked in petrol, or petrol in buckets, set 
on fire and used as a landing light for night flying. 

Flares, Parachute 

Magnesium light electrically fired and attached to a 
parachute, which is released near the ground to 
facilitate landing at night. 

Flares, Wing Tip 

Magnesium lights electrically fired and used to 
facilitate landing at night. 

Flattening Out 

A phrase used to describe the gradual decreasing of 
the gliding angle of a machine until it merges into 
the horizontal a few inches off the ground. 

Flight, A 

An organization consisting of a small group of 
machines. 

Flying Speed 

The speed of a machine through the air necessary 
to maintain its support. 

Forced Landing 

See "Landing." 

Formation Flying 

The practice of a group of machines keeping sta- 
tion in the air. 

Fuselage 

The body of a tractor machine. 



GLOSSARY 886 

Gap 

The distance between the upper and lower wings of 
a biplane. 

Gas Bag 

Slang term for airships. 

GlilDE 

To descend with the engine cut off with the machine 
under control and at approximately the flying level 
speed. 

Gmding Angle 

The angle that the fore-and-aft line of the machine 
makes with the horizon in order to make a correct 
gliding descent. 

Geound Speed 

The speed of the machine relative to the ground, 
which may be equal to, greater, or less than the air 
speed ; therefore, ground speed is equal to air speed 
-|- or — wind speed. 

Hangae 

An aeroplane shed. 

Hate, To Commit 

To be extreme in doing a thing, i.e., excessive stunt- 
ing near the ground. 

Heavy Handed 

Refers to a pilot who is clumsy with his controls 
and inclined to over-corrept. 

Height Indicatoe 

See "Altimeter." 

Hoik, To 

To make the machine climb steeply and suddenly. 

HOEIZON 

The limit of ground in view. 
HuN 

Slang term for a person learning to fly. 

Incidence, Angle of 

The angle that the chord of a wing makes with the 
direction of motion relative to the air. A particu- 
larly muddling term, as it i3 often measured as the 



S86 PRACTICAL FLYING 

distance in inches that the front spar is above the 
rear spar when the machine is in the flying-level 
position. 

Inclinometer 

An instrument for showing the angle of the machine 
relative to the ground. 

Induction 

The inlet stroke of the engine. 

Joy Stick 

See '^Control Lever." 

Kathedbal Angle 

A machine is said to possess a kathedral angle when 
the wings slope downwards from the centre of the 
machine. 

Keel Surface 

The side surface of a machine as opposed to the 
head-on surface. 

Kino Post 

A bracing strut generally found on the top of con- 
trolling surfaces, such as rudder, ailerons and ele- 
vator, in which case it also acts as a lever. 

Knock 

A peculiar noise emanating from the engine and in- 
dicating some kind of mechanical trouble. 

Knot 

A nautical mile per hour, i.e., it is wrong to speak 
of knots per hour. 

Landing 

The action of a machine in coming to earth. 

Landing, Forced 

The action of a machine in coming to earth other 
than at the will of the pilot, i.e., in the case of the 
engine failing. 

Leading Edge 

The point or entering position of a wing. 
Leeward 

Away from the wind. 
Leeway 

Lateral drift to leeward. 



GLOSSARY 887 

Left and Right 

Always refer to the left and right of the machine 
and engine as seen by the pilot sitting in his seat. 

LiPT 

The force exerted by the air on a plane in a direc- 
tion perpendicular, or nearly so, to the motion. 

Loo Book 

A book kept by pilots giving details of each flight. 

LONGEBONS 

The longitudinal members of the fuselage. 

Loop 

A manoeuvre in which the machine, after flying 
straight, does an upward and backward turn or 
circle, and then continues in the same direction as 
before. 

LuBBEB Line ob Lubbeb's Point 

A mark on the body of a compass corresponding 
with the fore and aft line of the machine. 

Machine 

The aeroplane as apart from the engine, 

MOTOB 

An incorrect term for the power imit or engine. 
M.P.H. 

Miles per hour. 
Nacelus 

The body of a pusher machine. 
Nose 

The front part of a machine. 

Nose Dive 

A very steep descent with or without engine. 

Nose Heavy 

Backward pressure required on the control lever to 
make the machine fly level. 

Nose Piece 

The front central portion of a rotary engine. 

OUTBIGGEB 

The framework connecting an elevator placed in 
front of the machine with Uie main planes. 



S88 PRACTICAL FLYING 

Pancake 

To drop to earth from a height of a few feet owing 
to losing flying speed and flattening out too soon. 

Peggino Down 

Securing a machine by rope to pegs in the ground 
so as to prevent it capsizing in a wind. 

Pilot 

A person controlling an aeroplane in the air. 

Pitch of a Propellee 

The forward distance that the propeller would 
travel if it were allowed to cut its way, without slip, 
through some medium such as butter. 

PiTOT Tube 

Consists of two tubes, one open to the air flow and 
the other protected. The other ends of the two 
tubes are connected to the air-speed indicator. One 
tube is called the pressure tube and the other the 
suction, or static, tube. 

Plane 

Term used to apply to the supporting surfaces of a 
flying machine. The planes may be cambered, as in 
the case of the wings, or flat, as in the case of the 
tail plane. 

Plane, Main 

The wings of the machine. 

Pocket Aie 

A disturbance in the air causing the machine to 
drop. 

Pbopelleb 

The airscrew driven by the engine which forces the 

machine through the air, generally known as the 

"Prop." 
Proteactoe 

An instrument for measuring angles. 

Pusher 

A machine in which the propeller is fitted behind the 

main planes. 
Quirk 

A person learning to fly ; slang term for pupil. 



GLOSSARY 239 

Race, To 

Refers to the practice of speeding up the revolu- 
tions of an engine to their maximum. 
Radiai. 

Refers to a type of engine in which the cylinders 
are set radially round the crankshaft, and are sta- 
tionary. 

Radius of Action 

The distance that a machine can fly from its starting 
point and return without replenishing the tanks. 
Greatly influenced by the wind factor. 

Remou 

A disturbance in the air. 

Remorque 

A motor trailer for carrying aeroplanes. 

Revs. 

Short for revolution. 

Revving 

Short for revolving. 

R.F. 

Representative fraction. A term indicating the 
scale of a map. 

R1B9 Compression 

A rib designed to act as a strut between the front 
and rear spars of a wing. 

Ribs 

The members used in a wing to give strength and 
shape in a fore and aft direction. Often called 
"former ribs." 

Right and Left 

Always refer to the right and left of the machine 
and engine as seen by the pilot sitting in his seat. 

Right and Left of a Machine 

Always refers to the machine as seen from the 
pilot's seat. 

Roll 

A manoeuvre in which the machine does a side- 
ways turn or circle, and then continues in the same 
direction as before, 



S4.S PRACTICAL FLYING 

Strainer 

See "Turnbuckle." The word can also refer to 
gauge or chamois leather used to strain petrol 
through before refilling the tanks. 

Streamline 

A shape of a body that offers the least resistance to 
its path through the air. 

Struts 

Vertical members uniting spars in upper and lower 

planes. 
Stunts 

Unusual or exaggerated evolutions in the air. 

«S'' Turns 

A series of steeply-banked right and left-hand 
gliding turns (with engine off). 

Switch 

A device for allowing or interrupting the pas- 
sage of electric current generally to the sparking 
plugs. 

Tachometer 

Engine revolution counter. 

Tail 

A group of planes set behind the main planes and 
consisting of both vertical and horizontal' surf aces, 
used to control the balance of the machine. 

Tail Boom 

The long spar connecting the main plane with the 
tail on a pusher machine. 

Tail Heavy 

Forward pressure required on the control lever to 
make the machine fly level. 

Tail Plane 

A fixed plane fitted parallel with the main plane, 
to which the elevator is attached. 

Tail Plane, Lifting 

A fixed plane parallel with the main plane to 
which the elevator is attached. It also carries some 
of the weight of the machine. 



GLOSSARY 24id 



e: 
z: 



X 






in: 



Tail Skid 

See "Skid." 



Taxying 

The progress of a machine on the ground with the 
engine running, though not fast enough to give 

ce; flying speed. 

Tee 

A ground sign indicating the direction of the wind. 

y^: Originally an arrow, but it was found to be an im- 

provement to widen the tip of the arrow until it be- 
came a T. The wind blows from the cross piece 
down the body of the T. 

Tendee 

A light motor lorry. 

Theottle Levee 

Controls the amount of explosive mixture enter- 
ing the engine. 

Ticket, To Take 

To pass an elementary flying test, and thus be reg- 
istered as a certified aviator. 



•T 



-P 



ToEQUE, Engine 

rj: The reaction of a propeller which tends to cause 
the machine to turn about its longitudinal axis in a 
direction opposite to that in which the propeller is 
revolving. 

Teactoe 

A machine in which the propeller is fitted in front 
of the main planes. 

Teaeling Edge 

* The rear edge of the wing. 

Teestle 

Wooden frames or scaffolds designed to support the 
tail or wings of a machine when repairs are being 
carried out. 

Tbiplane 

• An aeroplane with three pairs of wings, set one 
above the other. 



244 PRACTICAL FLYING 

Trueino Up 

Adjusting the rigging of a machine so as to correct 
its balance in the air. 

TUENBUCKLE 

A fitting used to adjust the tension of wires to which 
it is attached. Also called a strainer. 

, Undeecarriage or Underchassis 

That part of a machine which carries the weight of 

the aeroplane on the ground, and also takes the 

shock of landing. 
Veer, To 

A change of wind in a clockwise direction, i.e., from 

N. to E. 

Verticle Bank 

A loosely-applied phrase referring to any bank 
over 45 degrees. 

Veey's Light 

A coloured light fired as a signal from a special 
form of pistol. 

Volplane 

A glide. 

Warp 

The yarn running lengthwise in aeroplane fabric. 

Warp, To 

To move the control lever sideways so as to increase 
or decrease the incidence on a wing with a view to 
raising or lowering it. 

Wash In 

An increasing angle of incidence of a wing towards 
its wing tip. 

Wash Out 

A decreasing angle of incidence of a wing tbwards 
its wing tip. 

Weft 

The yarn running crosswise in aeroplane fabric. 

Windscreen 

A transparent screen mounted in front of the pilot 
and passenger to shield them from the rush of air 
by the machine in motion. 



GLOSSARY 245 

Wind Speed 

The speed of the wind. 

Wind Up 

To be frightened of going into the air. 
Wing 

The main supporting surface of an aeroplane. 

Wing Tip 

The right or left-hand extremity of a wing. 

Wing Tip Skids 

Semi-circular pieces of bamboo placed under the 
wing tips to take the shock off the wings, should 
the machine heel over on the ground. 

WiEE, Compensating or Balancing 

The wire connecting opposite ailerons of top or bot- 
tom planes. 

WiEES, CONTROI. 

See "Control Wires." 

WiEES, Drift 

Used to transmit the head resistance set up by the 
wings to the main body of the machine. 

Wires, Flying Drift 

Internal bracing wires of a wing connected from 
the front spar to the rear spar diagonally outwards 
in each cellule. 

Wires, Flying or Lift 

Used to transmit the weight of the machine to the 
wings. They lie upwards and outwards. 

Wires, Landing , 

Used to take the weight of the wings when the ma- 
chine is on the ground. They lie downwards and 
outwards. 

Wires, Landing Drift 

Internal bracing wires of a wing connected from the 
front spar to the rear spar diagonally towards each 
cellule. 

Wire, Snake 

Fine wire twisted round other wires to prevent the 
latter fouling the propeller, should they break. 






S46 PRACTICAL FLYING 

WiEES, WaEP 

Wires used to warp the ends of the wings to control 
the machine laterally. 
Zoom 

To ascend very steeply after flying level at full 
speed.